• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.149-158
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• 2022

This study aimed to investigate pesticide residues in 160 stalk and stem vegetables marketed in Northern Gyeonggi-do. The QuEChERS method using GC-MS/MS and LC-MS/MS was employed to analyze the residues of 341 pesticides in the samples. The maximum or lower than the residue limit was recorded in 75 samples (46.9%), while 4 samples (2.5%) exceeded the maximum residue limit (MRL). Thirty-nine kinds of residual pesticides were detected including fungicides (14), insecticides (22), herbicides (2), and plant growth regulator (1). Carbendazim and pendimethalin were the most frequelntly detected pesticides. Fenitrothion, procymidone, and diazinon exceeded MRL in garlic chives, and Welsh onion. This indicated that these vegetables along with water celery should be constantly monitored.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.221-230
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• 2024

Pesticide residues were monitored in dried red pepper and pepper powder samples purchased in Northern Gyeonggi-do and from domestic online markets. The QuEChERS method was used to prepare 88 samples. GC-MS/MS and LC-MS/MS were used to analyze 338 pesticide residues. In the study, pesticide residues were detected in 70 samples (79.5%), with residues exceeding the maximum residue limits (MRL) in 4 samples (4.5%). Pesticide levels exceeded the MRL in imported samples, with two samples of dried red pepper and two samples of pepper powder showing elevated levels. Among the 61 pesticides detected, tebuconazole, a fungicide was most frequently detected (52 times). Tricyclazole, which is used to control the main disease affecting rice, exceeding the MRL in 3 of 12 Vietnam-origin samples. Ethion exceeded the MRL in one Indian-origin sample. Both tricyclazole and ethion are banned for use in pepper products in Korea and are regulated under the positive list system (PLS). Conversely, pesticides detected in domestic samples were within the MRLs. Therefore, authorities should monitor pesticide residues in imported red pepper products.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.28-34
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• 2012

We analysed 149 samples of Korean traditional herbal tea materials. The 156 pesticides were analyzed by GC/ECD and NPD, detected pesticides were confirmed by GC-TOF/MS. Sample preparation was performed bv multi-residue analysis method of multiclass pesticides of the Korea Food Code. The residual pesticides were detected in 22 samples(14.8%), the highest detection frequency samples are lycium and jujube. Detected pesticides in Korean traditional herbal tea materials were chlorpyrifos (5 samples), chlorothalonil (3 samples), cypermethrin (3 samples), hexaconazol (3 samples) and cyhalothrin(3 samples). The pesticide types detected in Korean traditional herbal tea materials were organophosphorus(29.2%), pyrethroids(16.7%), organochlorines (12.5%) and triazoles(12.5%). The 5 samples(lycium, jujube, chrysanthemum, balloon-flower, milk vetch root) were detected pesticides below MRLs, 2 samples(cornus fruit, cnidium) were detected pesticides unnotificated MRLs.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.153-158
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• 2006

The contamination levels of 3-MCPD(3-Monochloropropane-1,2-diol) and 1,3-DCP(1,3-Dichloro-2-Propanol) in soy sauce, sauces was monitored. 105 samples were collected from June 2005 to August 2005 in Gyeonggi-do. 3-MCPD and 1,3-DCP were analyzed by GCMSD. As results, the detection range of 3-MCPD concentration was between 0.02 mg/kg and 0.27 mg/kg in soy sauce. However any samples were not detected with 1,3-DCP. The contaminated rates of 3-MCPD in soy sauce was 17.1%. Soy sauce is the representative vegetable protein hydrolyzed food. The reliable analytical method f3r the toxic 3-MCPD and 1,3-DCP in Soy sauce has been studied. The derivatization studies of 3-MCPD and 1,3-DCP were performed mainly as Silylation with BSA(N,O-Bis(trimethylsilyl)-acetamide). The retention times of derivative, BSA-MCPD, BSA-DCP were 11.30 and 10.12 minutes.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.83-88
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• 2018

The purpose of this study was to investigate and evaluate the safety of the wet tissues. In this study, we analyzed sterilizing preservatives and the presence of harmful substances in 62 wet tissue samples in the market. The contents of preservatives, formaldehyde and methanol were analyzed by HPLC and headspace-GC, respectively. Cetylpyridinium chloride was detected as 7-13 ppm in 5 samples. Sodium benzoate was detected in 46 samples ranging from 200 ppm to 3500 ppm, and 9 ppm of methylparahydroxy benzoate was detected in 1 sample. Propylparahydroxy benzoate was not detected in any samples. 5 ppm of methylchloroisothiazolinone and 140 ppm of methylisothiazolinone were detected in 1 sample. Formaldehyde was detected as $0.0069-1.796{\mu}g/g$ in 59 samples. Methanol was detected ranging from 2 ppm to 51 ppm in 22 samples, and 4 samples showed more than 20 ppm of the legal limit. The pH of the wet tissues was 4.0 to 8.2. Continuous investigation and monitoring are necessary to ensure safe distribution of products.

• Journal of the Korean Vacuum Society
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• v.18 no.3
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• pp.203-207
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• 2009

Copper is known as a replacement for aluminum wire which is used for semiconductor. Because specific resistance of Cu ($1.67{\mu}{\Omega}$-cm) is lower than that of Al ($2.66{\mu}{\Omega}$-cm), Cu reduce RC delay time. Although melting point of Cu($1085^{\circ}C$) is higher than melting point of Al, Cu have characteristic to easily react with Silicon(Si) in low temperature, and it isn't good at adhesive strength with Si. For above these reason, research of diffusion barrier to prevent reaction between Cu and Si and to raise adhesive strength is steadily advanced. Our study group have researched on W-C-N (tungsten-carbon-nitrogen) Diffusion barrier for preventing diffusion of Cu through semiconductor. By recent studies, It's reported that W-C-N diffusion barrier can even precent Cu and Si diffusing effectively at high temperature. In this treatise, we vaporized different proportion of N into diffusion barrier to research Cu's Electromigration based on the results and studied surface hardness in the heat process using nano scale indentation system. We gain that diffusion barrier containing nitrogen is more stable for Cu's electromigration and has stronger surface hardness in heat treatment process.

• Weed & Turfgrass Science
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• v.2 no.4
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• pp.352-357
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• 2013

A survey was performed to investigate major paddy field weeds and frequently used herbicides in Gyeonggi province, Korea in order to establish a system to efficiently control herbicide-resistant weeds. The dominant paddy field weeds included Echinochloa spp. (22%), Eleocharis kuroguwai (14%), Sagittaria trifolia (13%), Scirpus juncoides (12%), Monochoria vaginalis (9%) and Sagittaria pygmaea (7%), and the most widely used herbicides were butachlor 33% CS (25%), benzobicyclon + fentrazamide + imazosulfuron 11.5% SC (9%), cyclosulfamuron + mefenacet 22.2% SC (9%), butachlor 5% GR (6%), and oxadiazon 12% EC (6%) in Gyeonggi province, Korea. Many paddy rice growers considered S. juncoides, M. vaginalis, S. pygmaea and C. difformis as herbicide-resistant weeds. An extensive research deserves to be conducted to monitor occurrence of herbicideresistant paddy weeds in Gyeonggi province, Korea.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.257-263
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• 2012

Cosmetics using natural materials which was purchased in retail stores, distributed in Gyeonggi province(32 samples) and online through internet(24 samples) were analyzed by pesticide residues and target preservatives for assessing the safety of it. Natural or organic certifications was identified in 22 samples among 56 samples and most of them were Ecocert. Pesticide residues was detected in 3 samples among 56 samples and each compound and concentration was permethrin(0.6 mg/kg), tricyclazole(11.7 mg/kg) and malathion(0.05 mg/kg). All of it was purchased through internet. Target preservatives was detected in 13 samples among 56 samples and one of them was over the maximum allowed concentration and the rest of them were within the maximum allowed concentration of the respective preservatives. The compound which was over the maximum allowed concentration was benzoic acid and compounds which were within the maximum allowed concentration were sorbic acid, benzoic acid and methylparaben. They were all identified substances in products and the number of detected preservatives in retail stores were higher than online samples purchased through internet. As a result of this study, The method of analyzing pesticide residues and limit in cosmetics using natural materials should be set up as soon as possible and the monitoring about preservatives in cosmetics using natural materials should be conducted on continuously.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.184-205
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• 2019

Buddhism was introduced to Gyeonggi-Do early on and thus created various types of Buddhist culture there. Since the introduction of Buddhism into Gyeonggi-do, the there has been continuous construction of stone stupas. More stone stupas were built in southern Gyeonggi than in northern Gyeonggi-do. In particular, Anseong, Icheon, Yongin, and Yeoju were centers of construction. Looking at the characteristics of each period, stone stupas remain from the Unified Shilla Period to Joseon, indicating that stone stupas were steadily built during this period. The stone stupa corresponding to the Unified Shilla Period is meaningful in that it shows the northern limit of Shilla Buddhist culture. Since then, the stone stupas of the Goryeo Dynasty were actively constructed in the southern part of Gyeonggi-do in the early Goryeo Dynasty. By the late Goryeo Dynasty, the stupas were built throughout Gyeonggi-do, indicating that the construction of the stupa was active. In the Joseon Dynasty, stone stupas were built in temples near Hanyang and deeply related to the royal family. Stone pagodas were erected mainly on major traffic routes. Stone stupas built in Gyeonggi-do have a variety of artistic and historical significance.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.24-30
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• 2018

Norovirus infection is a leading cause of nonbacterial gastroenteritis outbreaks. New variants of GII.4 have emerged approximately every 2~3 years and have caused norovirus gastroenteritis pandemics globally. In this study, analysis and molecular genetic characteristics of the norovirus gastroenteritis outbreaks 2,917 samples in Gyeonggi-Do from 2014 to 2015. As a result, 247 samples out of 2,917 samples are positive for norovirus. Norovirus molecular genetic characteristics of the GI 8 types (GI-1, 2, 3, 4, 5, 6, 12, 14), GII 10 types (GII - 2, 3, 4, 5, 6, 11, 12, 14, 16, 17). Genome sequences of isolated noroviruses were similar to those of new GII.17 Kawasaki 2014 variants with 96.6 identity, suggesting that these viruses were imported from overseas. 44% of virus incidence was originated from school meal service. Therefore, a continuous monitoring and school sanitation should be required for preventing a massive virus outbreak.