• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.401-410
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• 2012

This study examines the authenticity discrimination of the circulated honey by using stable isotope ratio methods. In the case of domestic honey, the range of ${\delta}^{13}C$ for the samples labeled as pure honey was about -27- -21‰ at the $C_3$ origin, and the range of that for artificial honey was over -19‰ at the $C_4$ origin. The range of ${\delta}^{13}C$ for all imported honey was over -27- -23‰ originating from the $C_3$ plant. According to the nectar-source, ${\delta}^2H$ and ${\delta}^{18}O$ for domestic honey were significantly different for 6 and 5 groups, respectively. However, we could not explain the detailed relationship as well as the geographical feature of ${\delta}^2H$ and ${\delta}^{18}O$. The difference for ${\delta}^2H$ and ${\delta}^{18}O$ in the wide range of latitude, such as between Australia and Canada, was more or less shown. However, it was difficult to find out the trends of ${\delta}^2H$ and ${\delta}^{18}O$ for imported honey versus the geographical information in the similar latitudinal country.

• Korean Journal of Medicinal Crop Science
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• v.2 no.1
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• pp.51-59
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• 1994

This study was carried out to investigate the optimal propagation condition through stem node tissue culture of yam supplemented with concentration levels of growth regulators and activated charcoal in 1 /8MS white media. For shoot induction and plant regeneration from yam stem node tissue wre more effectivein combination of auxin, kinetin and activated charcoal than combination of auxin and kinetin. Shoot induction and plant regeneration were more effective in 1/8 medium suplemented with 1AA $2mg\;/\;\ell,\;kinetin\;2mg\;/\;\ell$ and activated charcoal $1g\;/\;\ell$ than in white medium, but in case of white medium, Shoot induction and plant regeneration wre effective in culture medium supplemented with NAAa $4mg\;/\;\ell,\;kinetin\;2mg\;/\;\ell$ and activated charcoal $1g\;/\;\ell$. Growth status in optimal propagation condition from yam stem node tissue brought the results of multiple plant, elongated plant height and increase in number of leaves and roots, but tissue culture effect by kinds of media in number of multiple plant were more effective in 1 /8MS medium than in white medium.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.14-30
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• 2020

This study focuses on the fact that pictorial maps in the late Joseon Dynasty were conceptual diagrams with the place names perceived by the people at the time of their production. In this regard, targeting on five pictorial maps, the humanistic landscape characteristics of Pyongyang, which had cultural identities such as a historically old, commercial, and Pungnyu(appreciation for the arts) city, were derived as follows. First, the historic legitimacy of Pyongyang Castle was represented by ritual and religious facilities. They include 'Dangunjeon' and 'Gijagung' related to the nation founder, 'Munmujeong': the remains of Goguryeo, 'Sajikdan' & 'Pyongyanggangdan': the place of the national rites, Hyanggyo and Seowon: education & rite functions, Buddhism and Taoist facilities, 'Yongsindang', 'Sanshindang', and 'Jesindan': folk religion facilities. Gija-related facilities, which became symbols of Pyongyang due to the importance of Small-Sinocentrism and Gija dignity tendency, were distributed throughout Pyongyang Castle though, the facilities related to King Dongmyeong of Goguryeo and the spaces of religion praying for blessings are spread in Bukseong and on the riverside of Daedonggang each. Second, as a Pyongando Province's economic center, Pyongyang's commercial landscape was represented by logistics and transportation facilities. The Daedonggang River, which was in charge of transportation functions, had many decks such as 'Yangmyeongpo', 'Cheongryongpo' and 'Waeseongjin' and bridges, such as 'Yeongjegyo' and 'Gangdonggyo', which connected major transportation routes. The road network was created in Oeseong area to facilitate logistics transportation and management, and many warehouses named after the jurisdiction of Pyongyangbu were distributed near the roads and Provincial Offices of the main gates. In addition, it was characterized by the urban area systematically divided with hierarchical roads, 'Bukjangnim' of willow trees planted on the main entrance roads of Pyongyang Castle, a linear landscape created by 'Simnijangnim' consisting of mixed forests with elm trees. Third, Pungnyu City is realized by the distribution of amusement facilities. The riverside of Daedonggang adjacent to Naeseong exhibits characteristics of artificial landscape such as a canal leading to the inside of the castle, a docking facility with embankments, and a port with cargo ships anchored. However, Bukseong of the natural surroundings had numerous pavilions and platforms such as 'Bubyeongnu', 'Eulmildae', 'Choeseungdae', 'Jebyeokjeong' and engraved letters such as 'Cheongnyubyeok', 'Jangbangho'. 'Osunjeong', 'Byeogwolji', 'Banwolji' near 'Sachang', and 'Aeryeondang', built on the island of a square pond, created waterscape in Naeseong invisible from the Daedonggang, and for practical purposes, ponds and repeated willow vegetation landscape related to Gija were placed in the western rampart of Jungseong. In addition, 'Seonyeondong', a cemetery of Gisaeng, located near by Chilseongmun, was used as poem titles and themes by literary people, contributing to the creation of the Pungnyu image of Pyongyang.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.408-415
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• 1999

When a zinc-oxide eugenol type sealer was placed in root canals treated previously with calcium hydroxide, acceleration of its setting and the yellowish discoloration were observed clinically. The purpose of this study was to evaluate the properties of calcium hydroxide-eugenol compound. Some physical properties of calcium hydroxide-eugenol compound were compared with a manufactured zinc-oxide eugenol based root canal sealer, Tubli-seal$^{(R)}$ in terms of water solubility, water sorption, film thickness and microleakage. Solubility and water sorption were determined by the use of the method described in American Dental Association Specification(ADAS) no. 57. Ten samples of each material were prepared into disks 20mm in diameter and 1.5mm in thickness. The samples were immersed in 50ml of distilled water at $37{\pm}1^{\circ}C$ for 7 days. The samples were then removed and placed in a desiccator. The values for solubility and water sorption were calculated using differences between the weights of same sample. Film thickness was determined by the use of the method described in ADAS no. 57 too. A small quantity of mixed cement was placed between two glass plates of which thickness was measured previously. 15Kg loading was applied and total thickness of the glass plates and the cement film was measured. The thickness difference was recorded as the material's film thickness. Microleakage was determined with a dye penetration method. Experimental materials were placed between the dentin surface of bovine tooth and the acrylic rod. These units were immersed in Pelican ink (W-Germany) for three days. Dye-penetrated dentin surfaces of bovine tooth were measured using the NIB Image 1.60 Macintosh program. The results are as follows: 1. Water solubility value of calcium hydroxide-eugenol compound (20.98${\pm}$2.94%) was statistically higher than those of Tubli-seal$^{(R)}$(2.52${\pm}$0.49%)(p<0.05). 2. Water sorption value of calcium hydroxide-eugenol compound (59.72${\pm}$17.75%) was statistically higher than those of Tubli-seal$^{(R)}$(3.15${\pm}$0.76%)(p<0.05). 3. Film thickness value of calcium hydroxide-eugenol compound (0.36${\pm}$0.03mm) was statistically higher than those of Tubli-seal$^{(R)}$(0.12${\pm}$0.1mm)(p<0.05). 4. Dye penetration value after 3 days-immersion of calcium hydroxide-eugenol compound(57.63${\pm}$25.85%) was statistically higher than those of Tubli-seal$^{(R)}$(28.05${\pm}$23.46%)(p<0.05).

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.32-40
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• 2015

This study was implemented to evaluate food safety on residual pesticides in agricultural products of Korea and to use as a data base for the establishment of food policy. A total of 196 pesticide upon these products were analyzed using multi class pesticide multiresidue methods of Korean Food Code, and 232 samples of 15 agricultural products collected from 9 regions were supplied for this study. In the results, 64 kinds of pesticides were detected in 53 samples, chlorpyrifos and procymidone of them were shown a high frequency of detection in the analyzed pesticides. Among them, two samples (chlorpyrifos in perilla leaves and picoxystrobin in peach) were detected over Maximum Residue Limits (MRLs). The levels of the detected pesticide residues were within safe levels. Also, the intake assessment for pesticide residues including chlorpyrifos at multi pesticide residue monitoring were carried out. The result showed that the ratio of EDI (estimated daily intake) to ADI (acceptable daily intake) was 0.001~0.902% which means that the detected pesticide residues were in a safe range so that residual pesticides in the agricultural products in Korea are properly controlled.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.467-473
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• 2007

Although the dominant land use at the Imha-dam watershed is forest areas, soil erosion has been increasing because of intensive agricultural activities performed at the fields located along the stream for easy-access to water supply and relatively favorable topography. In addition, steep topography at the Imha-dam watershed is also contributing increased soil erosion and sediment loads. At the Imha-dam watershed, outflow has increased sharply by the typhoons Rusa and Maemi in 2002, 2003 respectively. In this study, the Soil and Water Assessment Tool (SWAT) model was evaluated for simulation of flow and sediment behaviors with long-term temporal and spatial conditions. The precipitation data from eight precipitation observatories, located at Ilwol, Subi and etc., were used. There was no significant difference in monthly rainfall for 8 locations. However, there was slight differences in rainfall amounts and patterns in 2003 and 2004. The topographical map at 1:5000 scale from the National Geographic Information Institute was used to define watershed boundaries, the detailed soil map at 1:25,000 scale from the National Institute of Highland Agriculture and the land cover data from the Korea Institute of Water and Environment were used to simulate the hydrologic response and soil erosion and sediment behaviors. To evaluate hydrologic component of the SWAT model, calibration was performed for the period from Jan. 2002 to Dec. 2003, and validation for Jan. 2004 to Apr. 2005. The $R^2$ value and El value were 0.93 and 0.90 respectively for calibration period, and the $R^2$ value and El value for validation were 0.73 and 0.68 respectively. The $R^2$ value and El value of sediment yield data with the calibrated parameters was 0.89 and 0.84 respectively. The comparisons with the measured data showed that the SWAT model is applicable to simulate hydrology and sediment behaviors at Imha dam watershed. With proper representation of the Best Management Practices (BM Ps) in the SWAT model, the SWAT can be used for pre-evaluation of the cost-effective and sustainable soil erosion BMPs to solve sediment issues at the Imha-dam watershed. In Korea, the Universal Soil Loss Equation (USLE) has been used to estimate the soil loss for over 30 years. However, there are limitations in the field scale mdel, USLE when applied for watershed. Also, the soil loss changes temporarily and spatially, for example, the Imha-dam watershed. Thus, the SW AT model, capable of simulating hydrologic and soil erosion/sediment behaviors temporarily and spatially at watershed scale, should be used to solve the muddy water issues at the Imha-dam watershed to establish more effective muddy water reduction countermeasure.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.25-33
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• 2013

Clenbuterol and ractopamine, which are ${\beta}$-agonists, have been misused as a growth promoting agent in meat producing animals. Clenbuterol was banned for veterinary drug in Korea because of its problems regarding safety. Due to their adverse effects, such as cardiovascular and central nervous diseases on human health proper control and monitoring should be conducted. The existing analytical method of clenbuterol and ractopamine in the Food code was improved through our present study. The bovine muscle samples were subjected to enzymatic hydrolysis, extracted with ethyl acetate and defatted by hexane-methanol partitioning. A molecular imprinted polymer (MIP) solid phase extraction cartridge was used for clean-up and LC-MS/MS was operated in positive multiple reaction monitoring (MRM). Clenbuterol-$d_9$ and ractopamine-$d_3$ were used as an internal standard. The renewed method was validated according to the CODEX guideline. The limits of quantitation for clenbuterol and ractopamine were 0.2 and 0.5 ${\mu}g/kg$, respectively. The mean recoveries ranged in 104.2-113.5% for clenbuterol and in 107.6-118.1% for ractopamine. The improved method was able to save both time and expenses.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.399-404
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• 2016

The applicability of photostimulated-luminescence (PSL) and thermoluminescence (TL) for the detection of 12 food materials (potato, onion, garlic, dried pumpkin, black mushroom, black soybean, Cheongkukjang powder, sea mustard, pepper powder, Ramyun soup, corn tea, and green tea powder) irradiated with an electron beam, gamma ray, and X ray at a range of 0.15 to 10 kGy was investigated. For PSL, negative results (less than 700 photon counts (PCs)) were observed from non-irradiated foods while the irradiated foods showed intermediate (879 to 2,414 PCs) and/or positive (19,951 to 65,919,035 PCs) values. In all irradiated samples, the maximum peak of the TL glow curve was observed between 150 and $250^{\circ}C$. Our findings demonstrate the successful application of PSL and TL to determine whether food items were irradiated or not. However, there were no significant differences among the radiation sources.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.1-8
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• 2004

This study was executed to determine the cumulative dietary risk of PAHs exposed by food ingestion. Food samples including barbecued beef, barbecued pork, grilled chicken, ham, bacon and vegetable oil which were collected from food markets. These samples were saponified, extracted and cleaned up to purify PAHs, and then the purified sample solutions were analyzed by HPLC-FL. Generally, the levels of total PAHs in barbecued beef (0.2 ppb), bacon (0.3 ppb), barbecued pork (0.7 ppb), ham (0.8 ppb), and vegetable oil (1.2 ppb) were low, whereas the level of total PAHs in grilled chicken (9.3 ppb) was significantly high. For the exposure assessment of PAHs due to food ingestion, PAHs levels converted into TEQ$_{BaP}$, the average body weight for 20-73 age group and consumed levels of food proposed from report on the National Health and Nutrition Survey were used. The estimated lifetime average daily intake of dietary PAHs was 4.32${\times}$10$^{-4}$ $\mu\textrm{g}$-TEQ$_{BaP}$kg/day as the mean value. The dietary risk adjusted to cancer potency of benzo(a)pyrene as 7.3 (mg/kg/day)$^{-1}$ was 3.44${\times}$10$^{-6}$ based on current data.ata.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.916-923
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• 1998

To provide more information on the enteric pathogen Campylobacter jejuni in the view of food sanitation, survival characteristics of two strains of C. jejuni in the different conditions were investigated. When $10^7{\;}or{\;}10^3{\;}per{\;}ml$ of C. jejuni cells were inoculated in the supplemented Brucella broth and kept at $42^{\circ}C,{\;}25^{\circ}C{\;}and{\;}5^{\circ}C$ under the static aerobic condition for 7 days, organisms exponentially proliferated to $a{\;}>10^8$, even in the $10^3{\;}per{\;}ml$ inoculated-sample at $42^{\circ}C{\;}for{\;}1{\sim}2{\;}days$ and the considerable level of viability maintained during 7 days. At $5^{\circ}C$, most of the initial level of organisms survived at the early period and only $a{\;}<{\;}0.5-log_{10}$ cells decrease were observed during the 7 days. At $25^{\circ}C$, a remarkable number of C. jejuni declined within $1{\sim}2{\;}days$ and showed undetectable level of cells after 4 days. When sterile milk and minced chicken meat were artifically inoculated with $10^7{\;}per{\;}ml$ of C. jejuni, mostly, a $1-to{\;}2-log_{10}$ count decrease occurred at $42^{\circ}C{\;}and{\;}5^{\circ}C$ while $a{\;}>3{\;}log_{10}$ decrease at $25^{\circ}C$ during 7 days. Unexpectedly, no colonies appeared on the plate inoculated from the minced chicken meat sample kept at $42^{\circ}C$ after 4 days. The results suggest that C. jejuni contaminated to food can survive at the refrigeration temperature whereas they are sensitive to at the room temperature. Also, it is shown that the growth of C. jejuni at the optimal temperature may vary to the food sources.