• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.741-745
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• 2005

Pectin was dissolved in HCl, citric acid, and deionized distilled water (DW, 2%, v/v) and irradiated at different irradiation doses (2.5-50 kGy) by gamma ray to investigate its physicochemical characteristics and biological activity. Viscosity of pectin solution was significantly decreased by irradiation up to 10 kGy, then remained constant thereafter. Gamma-irradiation increased monosaccharide and polysaccharide levels up to 30-40 kDa. Electron donating ability of pectin solution was highest when DW was added and was increased by increasing irradiation dose (p<0.05). ${\beta}-Carotene$ bleaching assay revealed irradiation resulted in development of antioxidantive activity in pectin solution. Growth inhibition of cancer cell lines was observed in irradiated pectin solution in dose-dependent manner, with G36l showing the highest. Results suggested irradiation of pectin solution could be effective for preparation of functional pectin oligomer.

• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.37-56
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• 2001

As a preliminary study to establish fracture network model in crystalline rocks, detail investigation on fracture characteristics were performed. Five fracture sets were determined on the basis of regional survey of geological structures and fractures on outcrops. Among the fracture sets, S1 set has the highest density and longest trace length of fractures which was identified on surface in the study area. S4 and S5 sets are composed of foliations and foliation parallel shear joints of gneisses, which are very important sets at the aspect of weighting of fracture length. For characterization of subsurface fractures, detail core logging was performed to identify fractures and fracture zones from five boreholes. Acoustic televiewer logging and borehole geophysical loggings produced images, orientations and geophysical properties of fractures which intersect with boreholes. According to the result of the investigations, subsurface fractures can be grouped as three preferred orientations(B1, B2 and B3), which correspond to S1, S2 and S4/S5 of surface fracture sets, respectively. Actually, B1 set is expected to be intensely developed at subsurface. However, it has low frequency of intersection with boreholes due to its parallel or sub-parallel direction to boreholes. According to the inference of conductive fractures, B1 and B3 sets have possibilities of water flow and their intersection lines are also thought to consist of important conduits of groundwater flow. In particular, faults which are parallel to foliations control major groundwater flow in the study area.

• Journal of Oriental Physiology
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• v.14 no.2 s.20
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• pp.229-237
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• 1999

Hwanhonsan has been used for curing tumor as a Oriental medicine without any experimental evidence to support the rational basis for their clinical use. This experiment was carried out to evaluate the possible therapeutic or antitumoral effects of Hwanhonsan extract against cancer, and to study some mechanisms responsible for its effect. Some kind of tumors were induced by the typical application of 3-methylcholanthrene(MCA) or by the implantation of malignant tumor cells such as leukemia cells(3LL cells) or sarcoma cells(S180 cells) and FasII cells. Treatment of the Hwanhonsan extract(daily 1 mg/mouse, i.p.) was continued for 7 days prior to tumor induction and after that the treatment was lasted for 20 hrs. Against squamous cell carcinoma induced by MCA, Hwanhonsan decreased. not only the frequency of tumor production but also the number and weight of tumors per tumor bearing mice(TBM). Hwanhonsan also significantly suppressed the development of 3LL cells and S180 cells implanted tumors by frequency and their size, and some developed tumors were regressed by the continuous treatment of Hwanhonsan extract into TBM. However, when tumor was induced by FsaII cells implantation, the growth of implanted cells in mice was delayed by the water extract of Hwanhonsan until 7 days and then rapid growth ensued. In vitro treatment of Hwanhonsan extract had no inhibitory effect on the tumor induced by some kind of cell lines such as A431 cells strain but it significantly inhibited the proliferation of 3LL cells, S180 cells. These results suggested that Hwanhonsan extract exhibited a significant prophylactic benefits against tumors and its antitumor activity was manifested depending on the type of tumor cells.

• Korean Journal of Remote Sensing
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• v.26 no.2
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• pp.115-122
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• 2010

In this study, we analyzed ridge-runnel structure and ripple marks by using Envisat ASAR, JERS-1 SAR images and in-situ data in Mongsanpo intertidal flat located in Taean-Gun, Korea. A group of light-and-dark lines parallel to the shoreline, alternating 3-5 times, were observed in the intertidal flat in Envisat ASAR images. The patterns are related to ridge-runnel structure in the intertidal flat exposed to air. Well-drained runnels, typically with ripple marks, showed strong backscattering while runnels submerged by surface water or ridges, typically smooth with no ripple, have weak backscattering coefficients in Envisat ASAR images. In JERS-1 SAR images, however, the backscattering was very low on the entire intertidal flat and no ridge-runnel structure could be observed. The wavelengths of ripple marks measured from in-situ observations have ranges from 4 to 10 cm that satisfies the Bragg scattering condition of the 1st-order in Envisat ASAR images operating in C-band, but not in JERS-1 SAR that used L-band. Through this study using SAR images, we could successfully analyze the sedimentary conditions of intertidal flats with ridge-runnel and ripple marks which are not easily observed by optical sensors. It is expected that the results of this study with SAR images will contribute to the sedimentary research over intertidal flats.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.187-199
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• 2016

In order to delineate the soft ground distribution, an integrated geostatistical analysis was performed using the MASW (Multichannel Analysis of Surface Wave) which has the information of overall region and CPTu (Piezo Cone Penetration Test) which provides the direct information of the measuring point of the ground. MASW results were known to have close relationship with the ground stiffness. This correlation was confirmed through the comparison of MASW data obtained from two survey lines to the laboratory test with extracted soil samples. 3D physical property distribution in the study area was acquired by geostatistical integrated analysis with the data of tip resistance ($q_c$) and pore pressure (u) from the CPTu obtained at 6 points within the study area. The integrated analysis was conducted by applying the COSGSIM (Sequential Gaussian Co-Simulation) technology which can carry out the simulation in accordance with the spatial correlation between the MASW results and both tip resistance and pore pressure. Besides the locations of CPTu, borehole investigations were also conducted at two different positions. As a result, the N value of SPT and borehole log could be secured, so these data were used for the analysis of the geotechnical engineering accuracy of the integrated analysis result. For the verification of reliability of the 3D distribution of tip resistance and pore pressure secured through integrated analysis, the geotechnical information gained from the two drilling areas was compared, and the result showed extremely high correlation.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.420-432
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• 2021

This study was conducted to evaluate antioxidant, antibacterial, anti-inflammatory, and digestive enzyme activity in water extract (SAW) and 60% ethanol extract (SAE) from Stachys sieboldii. As the treatment concentration of each extract S. sieboldii extract increased, antibacterial and antioxidant activity increased. The total polyphenol and total flavonoid contents of SAW were 106.25 ± 0.94 mgGAE/g, 24.4 ± 0.24 mgQE/g and SAE were 124.61 ± 1.11 mgGAE/g, 45.2 ± 3.52 mgQE/g, respectively. The 400 ㎍/mL of SAW and SAE performed more than 53% protective effects against oxidative stress in HepG2 cell lines. All extracts were not showed cytotoxicity to RAW 264.7 cell line at 100 ㎍/mL. NO production was reduced to 44.3 ± 1.4% for SAW and 45.1 ± 1.0% for SAE at a concentration of 100 ㎍/mL. The production of inflammatory cytokines each TNF-α, IL-1β, and IL-6 was inhibited in a concentration-dependent. S. sieboldii extract did not showed Caco-2 cells cytotoxicity and inhibited NO production in concentration-dependent. As the concentration of the S. sieboldii extract increased of α-amylase and protease enzymes activity, which are digestive enzyme. As a result of the experiment, it is judged that it can be used as basic data for the development of health food using S. sieboldii.

• Journal of Life Science
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• v.29 no.2
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• pp.272-278
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• 2019

The silkworm performs sexual reproduction for the production of its healthy offsprings from generations to generations. Parthenogenesis in the silkworm, Bombyx mori acquires immense use in the development of outstanding homozygouse lines with higher viability, hybrid vigour, combining ability and less phenotypic variability, and it can serve as a powerful tool in controlling sex of the offsprings as well as a useful tool in selection of breeding schemes. However, naturally occuring parthenogenesis in silkworm could not be found so far. Fortunately, artificial induction of parthenogenesis is possible in silkworm. So, it is very important to find out novel methods for induction of parthenogenesis. We investigated to attempt to get a novel parthenogenetic method. Accordingly, parthenogenetic studies on between unfertilized in vivo ovarian eggs of live silkworm moth(novel) and unfertilized in vitro ovarian eggs(conventional) taken out from live silkworm moth were investigated by hot water ($46^{\circ}C$), hot air ($46^{\circ}C$) and low temperature ($0^{\circ}C$ and $-20^{\circ}C$) treatments. The best ratio of parthenogenetic eggs was obtained with in vivo ovarian eggs of live silkworm moth rather than with in vitro ovarian eggs taken out from live silkworm moth in all the treatments. The optimum exposure time absolutely depended upon the temperatures of treatments and the forms of in vivo or in vitro ovarian eggs. From these results, we expect that in vivo artificial parthenogenetic treatments on live silkworm moth will be useful for the higher induction of parthenogenesis in the silkworm, B. mori.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.81-87
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• 2021

Many merchant ships sail in the waters surrounding Jeju Island and many fishing vessels catch fish using gill nets, trolling lines, and so on. Meanwhile, marine waste has collected in the coastal waters of Jeju Island. However, there has been little research on the collection of marine waste in coastal waters. In this study, marine waste deposited in Jeju Island's northwest sea was collected using Jeju National University's training ship, and related vessels were analyzed for each gear type. According to the results, most coastal waters had abandoned fishing grounds, which were from fishing vessels, and a large proportion of them was gill net and trap fishing gear. To analyze how much marine waste is accumulating in a certain area and ship's stay time, we use automatic identification system (AIS) data to extract the time spent in the target sea, and the amount of marine waste per hour was analyzed in a unit distance of 1 ㎢. The average amount of marine waste generated per hour in the unit area was found to be 0.94 kg for gillnet fishing gear, 3.49 kg for trap fishing gear, 0.10 kg for trawl fishing gear, 0.11 kg for longline fishing gear, and 0.02 kg for other fishing gear.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.5
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• pp.357-371
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• 2023

In cable tunnel construction using TBM, the vertical shaft is an essential structure for entrance and exit of TBM equipment and power lines. Since a shaft penetrates the ground vertically, it often encounters rock mass. Blasting or rock splitting methods, which are mainly used to the rock excavation, cause public complaints due to the noise, vibration and road occupation. Therefore, mechanical excavation using vertical shaft excavation machine are considered as an alternative to the conventional methods. However, at the current level of technology, the vertical excavation machine has limitation in its performance when applied for high strength rock with a compressive strength of more than 120 MPa. In this study, the potential utilization of waterjet technology as an excavation assistance method was investigated to improve mechanical excavation performance in the hard rock formations. Rock cutting experiments were conducted to verify the cutting performance of the abrasive waterjet. Based on the experimental result, it was found that ensuring excavation performance with respect to changing in ground conditions can be achieved by adjusting waterjet parameters such as standoff distance, traverse speed and water pressure. In addition, based on the relationship between excavation performance, uniaxial compressive strength and RQD, it was suggested that excavation performance could be improved by artificially creating joints using the abrasive waterjet. It is expected that these research results can be utilized as fundamental data for the introduction of vertical shaft excavation machines in the future.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.90-90
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• 2022

Nicaragua is located in Central America, climatic conditions are considered tropical dry forest. Statistics reflex that in Nicaragua exits 24,000 rice farmers. National rice production only covers 73% of the national consumption. It exists two sowing system: irrigation and rainfed. Varieties used in both systems are mid-late maturity (120-135 days), there are 14 released varieties for irrigation, eight for rainfed, and eight landraces used in rainfed. The current breeding system (introduction of lines from Colombia) has increased the national production, however, has some limitation due to the lack of enough variability, reducing the proability of finding good genotypes and therefore the possibility of satisfying 100% of the demand. The purpose of this study was to analyze the problems that must be resolved in the short and long term to improve rice productivity in Nicaragua. In this paper we explain some proposal for an improvement plan. The selection of varieties with high adaptability to various cultivation environmental conditions it is necessary, also to thoroughly manage seed purity to supply certified seeds. In rice cultivation technology, it needs to improve seedling standing and weeding effect by improving soil leveling and water-saving cultivation technology. Also, proper fertilization and planting density must be established in irrigated and rain-fed areas. Furthermore, capacity must be strengthened by collecting and training with the most recent agricultural technology information, as well as by revitalizing the union rather than the individual farmer. It is necessary to develop varieties highly adaptable to the Nicaraguan cultivation environment, as well as to expand irrigation facilities and cultivation technology suitable for weather conditions in rain-fed areas. Last, it is necessary to maintain the consistency of agricultural policy for continuous and stable rice production in response to climate change events such as drought or intermittent heavy rain.