• Korean Journal of Heritage: History & Science
• /
• v.54 no.2
• /
• pp.4-21
• /
• 2021

A stone mold from the Sabi period of Baekje was excavated at the western tombs in Neungsan-ri, Buyeo where there was a recent excavation survey (2016). It was believed and reported that such stone molds were used for copper needles during the early Iron Age; however, a close re-examination of the form revealed that they were used for bifid ornamental hairpins. Given its casting form, the stone mold of Neungsan-ri is estimated to have been used to make bifid ornamental hairpins in a ∩ shape, narrowing down toward the tip. It is considered an artifact of the Goryeo dynasty. The stone used to make the bifid ornamental hairpin mold of Neungsan-ri was chlorite-schist, the principal minerals of which include chlorite, amphibole, and talc. Similar rocks are in nearby Buyeo (Oesan-myeon), Cheongyang, Gongju, and Yesan. They are mainly found between Jiseon-ri, Oesan-myeon, Buyeo, Sucheol-ri, Yesane-up, and Yesan. Nearly 70 bifid ornamental hairpins from the Goryeo dynasty were excavated at Neungsan-ri, Buyeo and the surrounding areas. Among them, the bronze ones excavated from the tombs of Songguk-ri, Buyeo are estimated to have been made using this mold as they closely resemble the Neungsan-ri mold. Stone was likely the preferred material for molds to make bronze artifacts as it was easy to sink a die. Regarding the bifid ornamental hairpin cast excavated in Neungsan-ri, they obtained stones in nearby areas 20~50km from their location, made bronze artifacts, and distributed them to nearby sites during the Goryeo dynasty. These artifacts suggest that the casting technology of using a stone mold was still employed then.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.38 no.4
• /
• pp.1-11
• /
• 2020

Noksan is a green area in the form of a hill located inside Gyeongbokgung Palace, unrecognized as a cultural heritage space. This study analyzed the literature and the actual site to derive its landscape meaning by examining the background for the formation of Noksan and how it changed. As a result, the identity of Noksan was related to the geomagnetic vein, pine forest, and deers, and the following are its landscape meaning. First, several ancient maps, including the 「Map of Gyeongbokgung Palace」 depicted the mountain range continuing from Baegaksan(Bugaksan) Mountain to areas inside Gyeongbokgung Palace, and Noksan is a forest located on the geomantic vein, which continues to Gangnyeongjeon Hall and Munsojeon Hall. On Bukgwoldo(Map of Gyeongbokgung Palace), Noksan is depicted with Yugujeong Pavilion, Namyeogo Storage, office for the manager of Noksan, the brook on north and south, and the wall. It can be understood as a prototypical landscape composed of minimal facilities and the forest. Second, the northern palace walls of Gyeongbokgung Palace were constructed in King Sejong's reign. The area behind Yeonjo(king's resting place) up to Sinmumun Gate(north gate of the palace) was regarded as the rear garden when Gyeongbokgung Palace was constructed. However, a new rear garden was built outside the Sinmumun Gate when the palace was rebuilt. Only Noksan maintained the geomantic vein under the circumstance. However, the geographical features changed enormously during the Japanese colonial era when they constructed a huge official residence in the rear garden outside the Sinmumun Gate and the residence of the governor-general and road in the site of the Blue House. Moreover, Noksan was severed from the foothill of Baegaksan Mountain when 'Cheongwadae-ro(road)' was constructed between the Blue House and Noksan in 1967. Third, the significant characteristics and conditions of the forest, which became the origin of Noksan, were identified based on the fact that the geomatic state of the northeastern side of Gyeongbokgung Palace, the naecheongnyong area in geomantic terms(the innermost 'dragon vein' among the veins that stretched out from the central mountain toward the left side), and they planted pine trees to reinforce the 'ground vein' and the fact that it was expressed as the 'Pine Field' before the Japanese Invasion of Korea in 1592. The pine forest, mixed with oaks, cherries, elms, and chestnuts, identified through the excavation investigation, can be understood as the original vegetation landscape. Noksan's topography changed; a brook disappeared due to mounding, and foreign species such as acacia and ornamental juniper were planted. Currently, pine trees' ratio decreased while the forest is composed of oaks, mixed deciduous trees, some ailanthus, and willow. Fourth, the fact the name, 'Noksan,' came from the deer, which symbolized spirit, longevity, eternal life, and royal authority, was confirmed through an article of The Korea Daily News titled 'One of the seven deers in Nokwon(deer garden) in Gyeongbokgung Palace starved to death.'

• Journal of the Korea Organic Resources Recycling Association
• /
• v.29 no.1
• /
• pp.19-27
• /
• 2021

Hydroponic farming is a method to grow a plant without soil. Plants can be grown on water or hydroponic growing media, and they are fed with mineral nutrient solutions, which are fertilizers dissolved into water. Hydroponic farming has the advantage of increasing plant productivity over conventional greenhouse farming. Previous studies of hydroponic nutrient wastewater from acyclic hydroponic farms pointed out that hydroponic nutrient wastewater contained residual nutrients, and they were drained to a nearby river bank which causes several environmental issues. Also, previous studies suggest that excessive use of the nutrient solution and disposal of used hydroponic growing media and crop wastes in hydroponic farms are major problems to hydroponic farming. This study was conducted to determine the impact of hydroponic nutrient wastewater, used hydroponic growing media, and crop wastes from acyclic hydroponic farms on the surrounding environment by analyzing water quality and soil analysis of the above three factors. Three soil cultivation farms and several hydroponic farms in the Gangwon C region were selected for this study. Samples of water and soils were collected from both inside and outside of each farm. Also, a sample of soil and leachate from crop waste piles stacked near the farm was collected for analysis. Hydroponic nutrient wastewater from acyclic hydroponic farm contained an average of 402 mg/L of total nitrogen (TN) concentration, and 77.4 mg/L of total phosphate (TP) concentration. The result of TP in hydroponic nutrient wastewater exceeds the living environmental standard of the river in enforcement decree of the framework act on environmental policy by 993.7 times. Also, it exceeds the standard of industrial wastewater discharge standards under the water environment conservation act by 6~19 times in TN, and 2~27 times in TP. Leachate from crop waste piles contained 11,828 times higher COD and 395~2662 times higher TP than the standard set by the living environmental standard of the river in enforcement decree of the framework act on environmental policy and exceeds 778 times higher TN and 5 times higher TP than the standard of industrial wastewater discharge standards under the water environment conservation act. For more precise studies of the impact of hydroponic nutrient wastewater, used hydroponic growing media, and crop wastes from acyclic hydroponic farms on the surrounding environment, additional information regarding a number of hydroponic farms, arable area(ha), hydroponic farming area, seasonal, weather, climate factor around the river, and the property of the area and farm is needed. Analysis of these factors and additional water and soil samples are needed for future studies.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.30 no.3
• /
• pp.13-22
• /
• 2022

In order to improve water quality of the water system contaminated with dyes, biochars prepared using discarded waste resources were applied in this study. Biochars with a large specific surface area were manufactured using street tree pruning products or waste wood, and were applied to remove an organic dye in synthetic water. Biochars were made by pyrolysis of typical street tree porch products (Platanas, Ginkgo, Aak) and waste wood under air-controlled conditions. Methylene blue (MB), which is widely used in phosphofibers, paper, leather, and cotton media, was selected in this study. The adsorption capacity of Platanas for MB was the highest and the q_max value obtained using the Langmuir model equation was 78.47 mg/g. In addition, the adsorption energy (E) (kJ/mol) of MB using the Dubinin-Radushkevich (D-R) model equation was 4.891 kJ/mol which was less than 8 kJ/mol (a criteria distinguishing physical adsorption from chemical adsorption). This result suggests a physical adsorption with weak interactions such as van der Waals force between the biochar and MB. In addition, the physical adsorption may resulted from that Platanas-based biohar has the largest specific surface area and pore volume. The ∆G value obtained through the adsorption experiment according to temperature variation was -3.67 to -7.68, which also suggests a physical adsorption. Considering these adsorption results, the adsorption of MB onto Platanas-based biochar seems to occur through physical adsorption. Overall, it was possible to suggest that adsorption capacity of the biochr prepared from this study was equal to or greater than that of commercial activated carbon reported in other studies.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.2
• /
• pp.167-176
• /
• 2021

When producing recycled asphalt mix, it is important that the old binder of reclaimed asphalt pavement(RAP) should be well melted during blending in the mixer. The recycled asphalt mix is produced by instant mixing(IM) of all materials(RAP, virgin asphalt and new aggregates) all together in the mixer. However, in the same recycled mix, the binder around RAP aggregate was found to show higher oxidation level than the binder coated around the virgin aggregate because the old binder of RAP was not rejuvenated properly while instant mixing. The partially-rejuvenated RAP binder is assumed to be a high stiffness point in IM recycled mix. In this study, the stage mixing(SM) method was introduced; blending RAP and virgin asphalt for the first stage, and then mixing all together with hot new aggregates for the second stage. To compare the effect of the two mixing methods on moisture resistance of recycled mixes, a statistical t-test was performed between SM and IM using indirect tensile strength(ITS) and tensile strength ratio(TSR). Three conditioning methods were used; a 16-h freezing and then 24-h submerging, 48-h submerging, and 72-h submerging in 60℃ water. It was found that the TSR(=ITS_wet/ITS_dry) values of the mixes prepared by SM was clearly higher than the IM mixes, and coefficients of variation of SM mixes were lower than the IM mixes. It was also observed that the ITS_WET of SM was significantly different from the IM at α=0.05 level by statistical t-test. The ITS_WET of SM mix was reduced less than the IM mix in severer conditioned mixes. Therefore, it was concluded that the stage mixing method was an important blending technique for producing better-quality of recycled asphalt mixes, which would show higher moisture resistance than the recycled mixes produced by conventional instant mixing.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.15-24
• /
• 2023

To examine the antitumor effect of proso millet grains, whether proso millet grains exert apoptotic activity against human cancer cells was investigated. When the cytotoxicity of 80% ethanol (EtOH) extract of proso millet grains was tested against various cancer cells using MTT assay, more potent cytotoxicity was observed against human breast cancer MDA-MB-231 cells than against other cancer cells. When the EtOH extract was evaporated to dryness, dissolved in water, and then further fractionated by sequential extraction using four organic solvents (n-hexane, methylene chloride, ethyl acetate, and n-butanol), the BuOH fraction exhibited the highest cytotoxicity against MDA-MB-231 cells. Along with the cytotoxicity, TUNEL-positive apoptotic nucleosomal DNA fragmentation and several apoptotic responses including BAK/BAX activation, mitochondria membrane potential (Δψm) loss, mitochondrial cytochrome c release into the cytosol, activation of caspase-8/-9/-3, and degradation of poly (ADP-ribose) polymerase (PARP) were detected. However, human normal mammary epithelial MCF-10A cells exhibited a significantly lesser extent of sensitivity compared to malignant MDA-MB-231 cells. Irrespective of Fas-associated death domain (FADD)-deficiency or caspase-8-deficiency, human T acute lymphoblastic leukemia Jurkat cells displayed similar sensitivities to the cytotoxicity of BuOH fraction, excluding an involvement of extrinsic apoptotic mechanism in the apoptosis induction. These results demonstrate that the cytotoxicity of BuOH fraction from proso millet grains against human breast cancer MDA-MB-231 cells is attributable to intrinsic apoptotic cell death resulting from BAK/BAX activation, and subsequent mediation of mitochondrial damage-dependent activation of caspase cascade.

• Korean Journal of Animal Reproduction
• /
• v.24 no.1
• /
• pp.89-95
• /
• 2000

This study was to establish an effective dilution technique in a vitrification of bovine blastocysts for the field trial. For vitrification, blastocysts were exposed in glycerol (G) and ethylene glycol (EG) mixture in m-DPBS supplemented with 10% FBS. Blastocysts were first exposed to 10% (v/v) G for 5 min, and subsequently were transferred to 10% G plus 20% EG (v/v) for 5 min. Finally, embryos were transferred to 25% G plus 25% EG (v/v) for 30 see and were placed in nitrogen vapor for 3 min, and then were plunged into L$N_2$. At thawing, the straw containing blastocysts was placed in air for 10 sec, and then plunged into a water bath at $25^{\circ}C$ until all ice had disappeared. They were placed in $25^{\circ}C$ and 36$^{\circ}C$ water according to treatment group for different time. Also, in vitro survival was assessed by the re-expansion and hatched rates at 24 hand 48 h postwarming, respectively. The results obtained in these experiments were summarized as follows; 1) In the survival rates of vitrified bovine blastocysts according to different dilution time at thawing, the data of 1 min group (86.6, 56.6%) were higher than those of other treatment groups (2 min; 93.5, 35.4%, 2.5 min; 76.9, 30.7%, 3 min; 88.8, 36.1% and 3.5 min; 83.7, 8.1%). 2) When the in vitro survival of vitrified groups according to different developmental stage was examined at 48 h after thawing using 1 min dilution method, the hatching rates of fast developed embryos (expanded blastocyst: 81.3%: early hatching blastocyst: 86.2%) were higher than that of delayed developed one (early blastocyst: 46.6%). 3) In addition, when the in vitro survival of vitrified groups according to different embryo age was compared, the hatched rates at 48 h after thawing of Day 7 (66.6%) and Day 8 embryos (60.0%) were significantly higher than that of Day 9 embryos (22.7%) (P＜0.05). These results demonstrate that vitrified bovine IVM/IVF/IVC blastocysts can be successfully survived in vitro using one-step dilution (1 min) method.

• Analytical Science and Technology
• /
• v.36 no.6
• /
• pp.291-299
• /
• 2023

The benzo[a]pyrene in edible oils is extracted using methods such as Liquid-liquid, soxhlet and ultrasound-assisted extraction. However these extraction methods have significant drawbacks, such as long extraction time and large amount of solvent usage. To overcome these drawbacks, this study attempted to improve the current complex benzo[a]pyrene analysis method by applying the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method that can be analyzed in a simple and short time. The QuEChERS method applied in this study includes extraction of benzo[a]pyrene into n-hexane saturated acetonitrile and n-hexane. After extraction and distribution using magnesium sulfate and sodium chloride, benzo[a]pyrene is analyzed by liquid chromatography with fluorescence detector (LC/FLR). As a result of method validation of the new method, the limit of detection (LOD) and quantification (LOQ) were 0.02 ㎍/kg and 0.05 ㎍/kg, respectively. The calibration curves were constructed using five levels (0.1~10 ㎍/kg) and coefficient (R²) was above 0.99. Mean recovery ratio was ranged from 74.5 to 79.3 % with a relative standard deviation (RSD) between 0.52 to 1.58 %. The accuracy and precision were 72.6~79.4 % and 0.14~7.20 %, respectively. All results satisfied the criteria ranges requested in the Food Safety Evaluation Department guidelines (2016) and AOAC official method of analysis (2023). Therefore, the analysis method presented in this study was a relatively simple pretreatment method compared to the existing analysis method, which reduced the analysis time and solvent use to 92 % and 96 %, respectively.

• Journal of Korean Society of Forest Science
• /
• v.48 no.1
• /
• pp.1-24
• /
• 1980

One of the most important basic problems for developing the new techniques in the field of road landscape planting practices in Korea, is to clarify, analyse, and evaluate the existing technical level through actual field survey on the various kinds of planting techniques. This study is, therefore, aimed at the good grasp of detail essences of the existing level of road landscape planting techniques through field investigations of the executed sites. In this study, emphasized efforts are made to the detail analysis and systematic rearrangements of such main subjects as; 1) principles and functions of the road landscape planting techniques; 2) essential elements in planning of it; 3) advanced practices in execution of planting of it; 4) and improved methods in maintenance of plants and lands as an entire system of road landscape planting techniques. The road landscape planting techniques could be explained as the planting and landscaping practices to improve the road function through introduction of plants (green-environment) on and around the roads. The importances of these techniques have been recognized by the landscape architects and road engineers, and they also emphasize not on]y the establishment of road landscape features but also conservation of human's life environment by planting of suitable trees, shrubs, and other vegetations around the roads. It is essentially required to improve the present p]anting practices for establishment of the beautiful road landscape features, specially in planning, design, execution, establishment, and maintenance of plantings of the environmental conservation belts, roadside trees, footpathes, median strips, traffic islands, interchanges, rest areas, and including the adjoining route roads.

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.3
• /
• pp.241-246
• /
• 2007

Purpose: $[^{11}C]6-OH-BTA-1$ ([N-methyl-$^{11}C$]2-(4'-methylaminophenyl)-6-hydroxybenzothiazole, 1), a -amyloid imaging agent for the diagnosis of Alzheimer's disease in PET, can be labeled with higher yield by a simple loop method. During the synthesis of $[^{11}C]1$, we found the formation of by-products in various solvents, e.g., methylethylketone (MEK), cyclohexanone (CHO), diethylketone (DEK), and dimethylformamide (DMF). Materials and Methods: In Automated radiosynthesis module, 1 mg of 4-aminophenyl-6-hydroxybenzothiazole (4) in 100 l of each solvent was reacted with $[^{11}C]methyl$ triflate in HPLC loop at room temperature (RT). The reaction mixture was separated by semi-preparative HPLC. Aliquots eluted at 14.4, 16.3 and 17.6 min were collected and analyzed by analytical HPLC and LC/MS spectrometer. Results: The labeling efficiencies of $[^{11}C]1$ were $86.0{\pm}5.5%$, $59.7{\pm}2.4%$, $29.9{\pm}1.8%$, and $7.6{\pm}0.5%$ in MEK, CHO, DEK and DMF, respectively. The LC/MS spectra of three products eluted at 14.4, 16.3 and 17.6 mins showed m/z peaks at 257.3 (M+1), 257.3 (M+1) and 271.3 (M+1), respectively, indicating their structures as 1, 2-(4'-aminophenyl)-6-methoxybenzothiazole (2) and by-product (3), respectively. Ratios of labeling efficiencies for the three products $([^{11}C]1:[^{11}C]2:[^{11}C]3)$ were $86.0{\pm}5.5%:5.0{\pm}3.4%:1.5{\pm}1.3%$ in MEK, $59.7{\pm}2.4%:4.7{\pm}3.2%:1.3{\pm}0.5%$ in CHO, $9.9{\pm}1.8%:2.0{\pm}0.7%:0.3{\pm}0.1%$ in DEK and $7.6{\pm}0.5%:0.0%:0.0%$ in DMF, respectively. Conclusion: The labeling efficiency of $[^{11}C]1$ was the highest when MEK was used as a reaction solvent. As results of mass spectrometry, 1 and 2 were conformed. 3 was presumed.