• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1619-1625
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• 2021

This paper demonstrates the possible nondestructive analysis of iron artifacts' metallurgical characteristics using neutron imaging. Ancient kingdoms of the Korean Peninsula used a direct smelting process for ore smelting and iron bloom production; however, the use of iron blooms was difficult because of their low strength and purity. For reinforcement, iron ingots were produced through refining and forge welding, which then underwent various processes to create different iron goods. To demonstrate the potential analysis using neutron imaging, while ensuring artifacts' safety, a sand iron ingot (SI-I) produced using ancient traditional iron making techniques and a sand iron knife (SI-K) made of SI-I were selected. SI-I was cut into 9 cm², whereas the entirety of SI-K was preserved for analysis. SI-I was found to have an average grain size of 3 ㎛, with observed α-Fe (ferrite) and pearlite with a body-centered cubic (BCC) lattice structure. SI-K had a grain size of 1-3 ㎛, α-Ferrite on its backside, and martensite with a body-centered tetragonal (BCT) structure on its blade. Results show that the sample's metallurgical characteristics can be identified through neutron imaging only, without losing any part of the valuable artifacts, indicating applicability to cultural artifacts requiring complete preservation.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.382-385
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• 2006

To know the effect of water treatment sludge (WTS) as a rice seedling culture soil, rice seeds are sown, germinated and grown on the culture soils mixed with different ratios of WTS to sand (100:0, 50:50, 30:70, respectively), and their growth effects was compared to that of control, commercial culture soil. When WTS is used as a culture soil for rice, the length and weight of the top part of rice seedling somewhat decreased than those of control treatment while their root length and weight in all WTS treatments significantly increased. Although phosphorus and potassium uptake of rice seedling in WTS treatments was slightly decreased, WTS treatment showed to develop root growth which is necessary in the seedling stage of all plane. Such a stimulatory effect on root growth of rice seedling was significant in the mixture ratio of 50% WTS to 50% sand.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.11-11
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• 2016

Penicillium species are commonly isolated from various outdoor and indoor environments, including marine environments such as sponges, algae and sand. Penicillium is especially important because numerous bioactive compounds have been isolated. Penicillium was the most common species in intertidal zone in Korea, however the diversity and ecological roles of Penicillium in intertidal zone are not clarified. We explored diversity and ecological roles of marine-derived Penicillium from tidal flat and sea sand in Korea. The diversity of marine-derived Penicillium from Korea was investigated using both culture-dependent and culture-independent approach by ${\beta}$-tubulin sequence. In addition, we evaluated optimal temperature, halo-tolerance, and enzyme activity of Penicillium strains, such as extracellular alginase, endoglucanase, ${\beta}$-glucosidase, and protease. For culture-dependent approach, a total of 182 strains of 62 Penicillium species were isolated, with 53 species being identified. The most common species was Penicillium oxalicum, followed by P. crustosum, P. brasilianum, P. koreense, and P. griseofulvum. Species richness and composition were not significantly different by season, substrates, and seaside. For culture-independent approach using Illumina sequencing, 73 OTUSs were detected. The most frequently observed species was P. antarcticum, followed by P. koreense, P. crustosum, and P. brevicompactum. Diversity of Penicillium was higher during winter season than during summer season and in western sea than in southern sea, respectively. Community structure was significantly different by season and sea side. 52 species were detected by both methods. Unique species were isolated from each of methods - 10 from culture methods and 21 from Illumina sequencing. Furthermore, salinity adaption of the Penicillium varied depending on species. Many Penicillium species showed endoglucanase, ${\beta}$-glucosidase, and protease activity. Some species including P. paneum and P. javanicum degraded the polycyclic aromatic hydrocarbons. Thus, our results demonstrate that intertidal zone in Korea harbors diverse Penicillium community and marine-derived Penicillium play important ecological roles as decomposers of organic material in marine environments.

• ALGAE
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• v.30 no.1
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• pp.35-47
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• 2015

The marine sand-dwelling dinoflagellate Polykrikos lebourae possesses obvious gold-brown pigmented plastids as well as taeniocyst-nematocyst complex structures. Despite of the presence of the visible plastids, previous attempts to establish this species in culture all failed and thus the unavailability of cultures of this species has posed a major obstacle to further detailed exploration of ecophysiology of the dinoflagellate. Here, we isolated P. lebourae from sandy sediment of an intertidal flat on Korean western coast, successfully established it in culture, and have been maintaining the stock culture over the past 3 years. Using this stock culture, we explored phagotrophy and potential prey resources of P. lebourae, growth and grazing responses of P. lebourae to different prey organisms, the effect of prey concentration on growth and grazing rates and gross growth efficiency (GGE) of P. lebourae when fed three different prey organisms, and the growth kinetics of P. lebourae under different light regimes. P. lebourae captured prey cells using a tow filament and then phagocytized them through the posterior end. The dinoflagellate was capable of ingesting a broad range of prey species varying in size, but not all prey species tested in this study supported its sustained growth. GGE of P. lebourae was extremely high at low prey concentration and moderate or low at high prey concentrations, indicating that P. lebourae grows heterotrophically at high prey concentrations but its growth seems to be more dependent on a certain growth factor or photosynthesis of plastids derived from the prey. In the presence of prey in excess, P. lebourae grew well at moderate light intensity of $40{\mu}mol$ photons $m^{-2}s^{-1}$, but did not grow at dim and high (10 or $120{\mu}mol$ photons $m^{-2}s^{-1}$) light intensities. Our results suggest that the benthic dinoflagellate P. lebourae is an obligate mixotroph, requiring both prey and light for sustained growth and survival.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.125-125
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• 2003

Recirculating aquaculture systems consist of different treatment compartments that maintain water quality within the ranges of commonly recommended for fish culture. This paper presents the common considerations in designing different treatment compartments as well as the engineering criteria in designing closed recirculating aquaculture system including a circular tank for fish culture, a sedimentation basin and a foam fractionator for solids removal, two styrofoam bead filters for TAN removal, a sand filter for nitrate removal, and aerators. The main purpose is to outline a common procedure in designing of closed recirculating aquaculture system for marine fish culture.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.787-792
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• 2016

Cutaneous leishmaniasis (CL) is a protozoan disease which is endemic in Iran. It is transmitted by the Phlebotomus sand fly. The eyelid is rarely involved possibly because the movement of the lids impedes the sand fly from biting the skin in this region. Here, we report 6 rare cases of eyelid CL. The patients were diagnosed by skin scraping, culture, and PCR from the lesions. Skin scraping examination showed Leishmania spp. amastigotes in the cytoplasm of macrophages. Culture examination was positive for Leishmania spp. PCR was positive for Leishmania major and Leishmania tropica. The lesions were disguised as basal cell carcinoma, chalazion, hordeolum, and impetigo. The patients were treated with intramuscular meglumine antimoniate (20 mg/kg/day) for at least 3 weeks. They showed a dramatic response, and the lesions almost completely disappeared. We emphasized the importance of clinical and diagnostic features of lesions, characterized the phylogenetic relationship of isolated parasites, and reviewed the literature on ocular leishmaniasis.

• Journal of Aquaculture
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• v.22 no.1
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• pp.118-121
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• 2009

This experiment was conducted to evaluate the effects of different substrates in rearing tank on growth and body composition of juvenile sea cucumber Apostichophus japonicus. Sea cucumber (average weight 3.6) were randomly distributed at a density of 10 juvenile per tank into nine tanks providing three different substrates including free-substrates, sand and wave-shaped plastic sheet as (shelter). Juveniles were fed with a commercial feed once in every 2 days for 8 weeks. At the end of the experiment, survival of sea cucumber was not affected by the presence of substrates (P>0.05). Weight gain and specific growth rate of sea cucumber reared in the tanks with sand were significantly higher than those of sea cucumber reared in the tanks with shelter and without substrate (P<0.05). Crude protein and crude lipid of whole body in sea cucumber reared in free-substrate tanks were significantly higher than those of juvenile reared in the tanks with other substrates (P<0.05). Higher ash content was obtained in sea cucumber reared in the tanks with sand compared to that of juvenile reared in the tanks with other substrates (P<0.05). The results of this study suggest that growth and proximate composition of whole body of sea cucumber was significantly affected by substrates. Among materials tested, sand may be a proper substrate for sea cucumber culture.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.236-247
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• 1996

The main objective of this study was to evaluate the effectiveness of nutrient solutions, substrates, and nutrient solution concentrations in substrate culture of radish(Raphanus sativus L. var. sativus). Cooper's, Hoagland ＆ Arnon' 5, and Yamazaki's solution were used to determine the most suitable nutrient solution in deep flow culture(DFC). In result, Yamazaki's solution treatment showed better results than Hoagland's and Cooper's solution treatments in leaf length, leaf number, shoot and root fresh weights. Cooper's solution was much worse than others. Root shape index were low as 0.6 in all treatments. The selection of suitable was conducted among 14 kinds of substrates which were used commercially, such as sand, perlite and peatmoss, in substrates culture. Sand was the most proper in radish growth and shortened the growth periods. Sand also showed better results then others in leaf length, leaf number, shoot and root fresh weight. On the contrary, radish growth in peatmoss was the worst. Generally, root shape index was higher in substrate than in DFC. In order to investigate the suitable ionic strength in radish, Yamazaki's solution was treated with EC of 0.5, 1.0, 1.5, and 2.0 mS/cm. Generally radish growth above 1.0 mS/cm concentration was good, and the best result was shown in 1.5 mS/cm. Vitamin C contents were not significantly different in the roots of radish grown under 1.0 mS/cm or more. The highest vitamin C content was shown in 0.5 mS/cm, and so was thiocyanate content. Anthocyanin contents increased with the increase of the ionic strength in nutrient solution. Mineral nutrient contents had no significant statistical differences between the treatments, but potassium content was remarkably high in 1.5 mS/cm.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.447-452
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• 2009

A bacterium, which was named to be Bacillus cereus A-139, secreting auxin was isolated from the east coast sand dunes in Korea. The secretion of auxin was confirmed by HPLC. When cultured in LB broth, Bacillus cereus A-139 produced $16.12\;{\mu}$g/mL auxin after 8 days in LB broth. Bacillus cereus A-139 produced $49\;{\mu}$g/mL auxin and $162.6\;{\mu}$g/mL by the addition of 2% tryptone and 0.1% tryptophan, respectively. The root growth of Arabidopsis thaliana was retarded by Bacillus cereus A-139 culture broth up to 57% but the formation of lateral roots was increased up to almost twice after 4 days incubation. Also the formation of lateral roots of mung bean was increased up to 57% after 10 days incubation.

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.143-151
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• 1990

This study was carried out to investigate the influence of different types of nutrient solutions and culture media on the growth and quality of cucumber(Cucumis sativus L.) and tomato(Lycopersicon esculentum Mill.). The results are summarized as follows : 1. The growth and yield of cucumber and tomato were best in rockwool culture with Cooper solution. 2. In sand-sack culture, growth and yield of cucumber and tomato were higher with compound fertillzer solution. 3. Growth and yield of cucumber and tomato were more effective in rockwool culture than in soil culture in early growth stages, and vice versa in later growth stages. 4. Vitamin C contents of cucumber and tomato showed no differences between soil cultures and hydroponics, except rockwool culture with compound fertilizer solution. 5. The dry weight, total-N, and mineral content of cucumber and tomato showed no differences among all types of hydroponics.