• 한국습지학회지
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• 제9권1호
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• pp.107-114
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• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• Molecular & Cellular Toxicology
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• 제5권3호
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• pp.179-186
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• 2009

Hexachlorobenzene (HCB) is a bioaccumulative, persistent, and toxic pollutant. HCB is one of the 12 priority of Persistent Organic Pollutants (POPs) intended for global action by the United Nations Environment Program (UNEP) Governing Council. POPs are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Some of HCB is ubiquitous in air, water, soil, and biological matrices, as well as in major environmental compartments. HCB has effects on various organs such as thyroid, bone, skin, kidneys and blood cells and especially, revealed strong toxicity to liver. In this study, we identified genes related to hepatotoxiciy induced by HCB in human hepatocellular carcinoma (HepG2) cells using microarray and gene ontology (GO) analysis. Through microarray analysis, we identified 96 up- and 617 down-regulated genes changed by more than 1.5-fold by HCB. And after GO analysis, we determined several key pathways which known as related to hepatotoxicity such as metabolism of xenobiotics by cytochrome P450, complement and coagulation cascades, and tight junction. Thus, our present study suggests that genes expressed by HCB may provide a clue for hepatotoxic mechanism of HCB and gene expression profiling by toxicogenomic analysis also affords promising opportunities to reveal potential new mechanistic markers of toxicity.

• 한국수산과학회지
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• 제35권2호
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• pp.110-114
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• 2002

유용 양식어류인 틸라피아를 대상으로 어체중당 1일 0.05, 0.25 및 0.50mg/kg의 HCB와 PCBs의 경 구투여에 의해 30일 동안 혈액성상 및 혈액화학적 변동을 조사하였다. HCB의 투여에 의한 틸라피아의 RBC 수는 20일 이후 0.50mg/kg, 30일째는 0.25mg/kg의 농도, hemoglobin 농도와 hematocrit 값은 20일 이후 0.50mg/kg 농도에서 유의한 감소를 나타냈다. PCBs의 투여에 의한 틸라피아의 RBC 수, hemoglobin 농도 및 hematocrit 값은 20일 이후 0.25mg/kg 이상의 농도에서 유의한 감소를 나타냈다. 혈청 무기성분인 calcium, magnesium 및 inorganic phosphorus 농도는 HCB를 투여한 모든 실험에서 뚜렷한 차이가 인정되지 않았다. 또한, PCBs를 투여한 모든 실험에서도 magnesium과 inorganic phosphorus 농도의 변동은 관찰되지 않았으나, calcium 농도는 20일 이후 0.50mg/kg 농도, 30일째는 0.25mg/kg 이상의 농도에서 유의한 감소를 나타냈다 HCB의 경구투여에 의한 혈청 total protein 농도는 30일째 0.50mg/kg 농도에서, PCBs의 경구투여에 의해서는 20일 이후 0.25mgfg 이상의 농도에서 유의하게 감소하였다. HCB 및 PCBs의 경구투여에 의한 glucose 농도는 20일 이후 0.25mg/kg 이상의 농도에서 유의한 증가를 나타냈다. HCB 및 PCBs의 경구 투여에 의한 GOT와 GPT 활성은 20일 이후의 0.50mg/kg에서 유의한 증가를 나타냈다. 결론적으로 HCB 및 PCBs의 경구투여에 의한 틸라피아의 혈액화학적 변동은 0.25 mg/kg 농도 이상에서 적어도 20일 후부터 영향을 받을 것으로 생각된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.601-602
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• 2015

Interruption of AC is easier due to natural occuring of zero crossings. In DC, zero crossings is achieved by Forced commutation technique. In this paper an alternative counter voltage(ACV) DC Hybrid Circuit breaker(DC-HCB) is modeled using EMTP/ATP tool, Results show that, ACV DC-HCB can interrupt DC with in 5ms with a source voltage of upto 1 KV.

• 대한환경공학회지
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• 제34권5호
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• pp.335-344
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• 2012

본 연구에서는 우리나라 대표적인 4대강 수계의 퇴적물을 대상으로 HCB와 DDTs 농도분포 특성에 대해 검토하였다. HCB 농도는 한강 0.41~3.80(평균 1.58) ng/g, 낙동강 0.08~6.09(평균 0.90) ng/g, 금강 0.02~0.97(평균 0.30) ng/g, 영산강 0.28~0.59(평균 0.42) ng/g, 섬진강 0.23~0.48(평균 0.32) ng/g 으로 검출되었다. DDTs 농도는 한강 0.67~14.20(평균 4.76) ng/g, 낙동강 N.D.~10.36(평균 1.81) ng/g, 금강 N.D.~7.26(평균 1.87) ng/g, 영산강 N.D.~3.12(평균 1.08) ng/g 및 섬진강에서 0.02~2.04(평균 0.56) ng/g으로 검출되었다. 우리나라 하천 퇴적물 중 HCB와 DDTs 농도는 다른 나라의 강이나 하구언 퇴적물 농도와 비교해도 상대적으로 낮게 나타났다. 퇴적물 시료에서 검출된 농도를 미국해양기상연구소가 제시한 퇴적물권고기준치와 비교한 결과 HCB의 농도는 모두 ERL 값에 크게 미치지 않는 것으로 조사되었다. DDTs의 경우 46개 시료에서 ERL(1.58 ng/g)을 초과하는 농도를 나타내어 현재 퇴적물 중 DDTs 농도가 저서생물에 위해한 영향을 줄 것으로 예상되는 수준은 아니나 지속적인 관찰이 요구되는 것으로 판단되었다.

• 한국환경과학회지
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• 제14권2호
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• pp.121-128
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• 2005

Hexachlorobenzene (HCB) was analyzed in various marine organisms of Korea. HCB was detected in all organism samples with residual concentrations from 0.51 to 222 pg/g wet weight. HCB residue was the highest content in crustacean, and followed by bivalves, fish, cephalopods and gastropods. The residues were comparable to or lower than those in marine organisms of other countries. Daily dietary intake of HCB from seafood was estimated to be 13.4 pg/kg body weight/day. The relative contribution of taxonomic group to the total dietary intake of HCB were in the order of crustaceans $(40.1\%)$, bivalves $(34.2\%)$, fish $(23.1\%)$, cephalopods $(2.22\%)$, and gastropods $(0.38\%)$. Daily dietary intake of HCB expressed as toxic equivalent (TEQ) value was estimated to be $1.34\times10^{-3}pg$ TEQ/kg body weight/day. This value did not exceed tolerable daily intake (TDI) proposed by the WHO, the UK toxicity committee and the KFDA. Cancer risk and target hazard quotient (THQ) due to the consumption of the marine organism in Korean adult population were evaluated using the exposure equation of food ingestion. This result suggests that dietary intake of HCB by the consumption of Korean seafood seems to be safe for human health with negligible cancer and non-cancer risks so far.

• 상하수도학회지
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• 제35권4호
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• pp.301-309
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• 2021

Chitosan, natural organic polymer, has been applied in water treatment as adsorbent due to non-toxic for human being. The amino group as functional group, can interacts with cation and anion at the same time. The prepared chitosan bead (HCB) was crosslinked to increase chemical stability (HCB-G) and both HCB and HCB-G were prepared to increase physical strength by drying referred to DCB and DCB-G, respectively. The adsorption effect for crosslinking and drying for four types of chitosan bead was tested using pseudo fist order (PFO), pseudo second order (PSO), and intraparticle diffusion model (ID). Regardless of PFO and PSO, the order of K, rate constant, is as followed: HCB > HCB-G > DCB > DCB-G for Cu(II) and phosphate. Drying leading to contraction of bead significantly reduced adsorption rate due to reduce the porosity of chitosan. In addition, crosslingking also negatively effect on adsorption rate. When compared with Cu(II) using hydrogel bead, phosphate showed higher value than Cu(II) for PFO and PSO. The application of ID showed that both hydrogel beads (HCB and HCB-G) obtained a very low R² ranging to 0.37 to 0.81, while R² can be obtained to over 0.9 for DCB and DCB-G, indicting ID is appropriate for low adsorption rate.

• 농약과학회지
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• 제4권4호
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• pp.31-34
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• 2000

농약제조에 사용되는 chlorothalonil 원제 중 유해 부성분으로 규제하고 있는 hexachlorobenzene (HCB)의 함량을 조사하였다. 1996년부터 2000년까지 5년간에 걸쳐 3개 원제공급선으로부터 시료 32점을 발취하여 전자포획검출기(GLC/ECD)를 이용한 gas chromatography법으로 분석한 결과 HCB 함량은 최저 0.0036%부터 최고 0.0330%까지의 분포를 보였으며, 평균치는 0.0219%이었다. 발취시료 중에서 규제기준인 0.05%를 초과한 시료는 없었다. 또한 국내에서 1995년부터 1999년까지 5년간 chlorothalonil의 사용량을 기준하여 HCB의 농업환경 중에 투입된 양을 산출한 결과 연평균 약 77kg이었다.

• 대한바이러스학회지
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• 제28권2호
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• pp.129-138
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• 1998

Bovine growth hormone (bGH) gene was expressed in an insect Spodoptera frugiperda cell line using a Baculovirus, Hyphantria cunea nuclear polyhedrosis virus (HcNPV). The bGH gene in pbGH plasmid was sequenced and amplified by PCR technique with two primers containing NcoI sites. The bGH gene consisted of 654 bp (217 amino acid residues), the 5'-untranslated region of the cloned bGH cDNA contains 56 bp, and the 3'-untranslated region contains 145 bp and two pallindromic regions. The amplified bGH gene DNA fragment (654 bp) was inserted into the NcoI site of the pHcEVII vector, which was named pHcbGH. The pHcbGH transfer vector DNA and the wild type HcNPV DNA were cotransfected into S. frugiperda cells to construct a recombinant virus. Eight recombinant viruses were selected and named HcbGH. One clone, HcbGH-4-1 showed largest plaque size, therefore the recombinant virus was further studied. The multiplication pattern of the recombinant HcbGH-4-1 was similar to that of the wild type HcNPV. The bGH gene DNA in the HcbGH-4-1 recombinant was confirmed by Southern blot hybridization. The amount of the bGH (217 amino acid residues, 21 kDa) produced in S. frugiperda cells infected with the HcbGH-4-1 recombinant was approximately 5.5 ng per ml ($10^6$ cells) by radioimmunoassay.

• 한국컴퓨터정보학회논문지
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• 제12권4호
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• pp.11-19
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• 2007

본 논문에서는 CB 트라이와 HCB 트라이의 단점을 보완한 RCB 트라이를 제안한다. 먼저 CB 트라이의 경우 처음으로 축약된 구조를 시도하였으나 데이터의 양이 증가함에 따라 트리의 균형을 맞추기 위해 사용되는 더미노드들로 인해 삽입에 상당한 어려움을 가지고 있다. 반면 계층적으로 표현한 HCB트라이는 map이 오른쪽으로 증가하는 것을 막기 위해 일정 깊이를 주어 깊이에 다다르면 새로운 트리를 만들어 연결시키는 방법을 이용하였다. 결과적으로 입력과 검색 속도를 상당히 빠르게 진전시킬 수 있었으나 CB트라이와 마찬가지로 더미노드를 사용하고 여러 트리의 링크를 사용하기 때문에 저장공간이 커지는 단점을 안고 있다. 본 논문에서 제안한 RCB트라이는 더미노드를 완전히 없애 treemap을 약 35%정도 줄일 수 있었고 HCB트라이에 비해 전체 색인의 크기를 절반으로 줄였다.