• Title/Summary/Keyword: Smelt

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Lead Exposure Status of Smelt Process Workers in Steelmaking using Scrap Iron (제강공장 고철 용해공정 근로자의 납 노출실태)

  • Gu, Dongchul;Lee, Jaehwan;Han, Areum;Kim, Hyunju;Lee, Suyeon;Yun, Soonyoung;Lee, Chae Kwan
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.2
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    • pp.164-168
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    • 2013
  • Objectives: This study was aimed at the examination of the lead exposure status of smelting process workers in steelmaking using scrap iron. Methods: The study was conducted from July to September 2012 by means of measurements taken during the smelting process, with 45 minutes set for a one-time smelting work cycle when it comes to personal air sample and area air sample. As such, daily work hours were classified into 360 minutes for measurement. The analysis of lead concentration was conducted using AAs based on the NIOSH 7300 method. Results: In the case of the personal specimens that were subjected to periodical measurement 45 minutes per one session during the smelting process, 40 out of 42 specimens measured were found to contain lead, with an average concentration level of $0.028mg/m^3$ (Max: $0.182mg/m^3$, Min: $0.005mg/m^3$, TWA-more than 50%: 4 out of 6 units). In the case of regional specimens, lead was detected in 45 out of 48 specimens measured, with an average concentration level of $0.037mg/m^3$ (Max: $0.220mg/m^3$, Min: $0.007mg/m^3$ ). In the case of regional specimens subjected to measurement using a day as the work cycle, lead was detected in 15 out of 15 specimens measured, with an average concentration level of $0.049mg/m^3$ (Max: $0.478mg/m^3$, Min: $0.005mg/m^3$ ). Conclusions: It concluded that smelting process workers in steelmaking are exposed to lead because scrap iron is used as a raw material. It is thus necessary to introduce legal management to prevent occupation-related disease in smelting process workers in steelmaking.

Metallurgical Analysis for Non-ferrous Smelting Slag Collected from Seosan Area (서산 지역 수습 비철제련 슬래그의 금속학적 특성 분석)

  • Lee, Hye Jin;Lee, Hye Youn;Lee, So Dam;Cho, Nam Chul
    • Journal of Conservation Science
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    • v.32 no.2
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    • pp.189-202
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    • 2016
  • To figure out the material characteristics about slag and raw materials which are founded in iron product sites in Seosan area, we used XRF, EDS to analysis chemical compositions. Also we observe the microstructure by microscope and SEM. To identify the mineral component, XRD analysis was used and to assume the provenance of the raw material, lead isotope ratio analysis was used. From the results, we figure out that slags are non-ferrous created when metal was refined. Also, main tissue of slags were Fayalite, Galena, Magnetite, and raw materials were identified as mineral of Galena, Anglesite, Pyrite etc. From the result about lead isotope ratio analysis, we found out most samples are classified as the Western Gyeonggi massif in South Korea. Especially three of raw materials and slag samples which collected in the Seosan Doseongri was presumed to be the provenance. We figure out that slags we analyzed were made in non-ferrous metal smelting process and especially that were more likely to smelt from Seosan Doseongri. If various slags in this area are analysed by someone, It will contribute understanding non-ferrous metal refining process as well as metal refining which are composed.

A Study on Major Local Foods in Gwangju.Jeonam Area (광주.전남지역의 주요 특산식품에 대한 연구)

  • Kim, Jeong-Ok;Choi, Cha-Ran;Shin, Mal-Shick
    • Korean Journal of Human Ecology
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    • v.15 no.2
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    • pp.327-339
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    • 2006
  • We have investigated the distribution of major local foods cultivated in Gwangju City and Jeollanam-Do in order to understand the food culture of Honam region. The local foods were divided into 4 classes: agricultural, aquatic, animal and other products. 124 species of local foods, including 51 agricultural products, 50 aquatic products, 6 animal products and 17 others, were identified from this region. In Jeollanam-Do area, the agricultural products have a variety of fruits and vegetables, and aquatic products have fishes. In particular, rice, cucumber, pear, anchovy, oyster, laver, oyster mushroom, shiitake mushroom, and honey were determined as major local foods in Jeollanam-Do area. Note that Mudeungsan watermelon is cultivated in Gwangju, and sweet smelt and cat fish caught only in Sumjin river and Tamjin river area. In recent years, pumpkin (Cucurbita maxima Duchesne), paprika, kiwi and melon were determined as major local foods in Jeollanam-Do. Furthermore, branding strategy of agricultural and animal products can be said to improve. Wild types of aquatic productions, mushrooms and wild edible greens have been decreasing, whereas cultivated production increasing. The kinds of special local foods in Gwangju City and Jeollanamdo area were influenced by geographical, religious and social factors.

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Scientific Analysis of Slags and Furnace Wall collected from Iron Production Site at Suryong-ri Wonmorongi in Chungju (충주 수룡리 원모롱이 야철지 수습 철재 및 노벽의 과학적 분석)

  • Cho, Hyun-Kyung;Cho, Nam-Chul;Kang, Dai Ill
    • Journal of Conservation Science
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    • v.29 no.2
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    • pp.139-147
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    • 2013
  • This study focused on iron making related information through analyzing slags and furnace wall collected from iron production site of Suryong-ri Wonmorongi, Chungju. Total Fe content of slags were from 36.98% to 44.47% and this range was general recovery rate of iron in ancient. Compounds of calcium included slags was supposed to add intentionally during smelting process as deoxidation agent in order that these helped to separate iron from impurities. Furnace wall didn't make of high alumina clay because of low $Al_2O_3$. Microstructure and main components of slags show that No. 1 to 3 slags with fayalite and wustite were products of iron ore smelting. However, No.4 slag is more likely to smelt by iron sand because of ulvospinel with $TiO_2$ in No. 4 slag. Therefore, iron ore were not only used but iron sand in smelting and furnace wall made of general clay with low $Al_2O_3$ content in this area.

A Case of Clonorchis Sinensis with Multiple Low Echogenic Nodules in a Child (소아에서 진단된 다발성 저음영 결절 형태를 보인 간흡충증 1례)

  • Hwang, Young Jun;Han, Man Yong;Ha, Doo Hoe
    • Pediatric Infection and Vaccine
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    • v.8 no.1
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    • pp.123-128
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    • 2001
  • Clonorchiasis, known as the parasitic fluke in the intrahepatic bile ducts, occurs throughout Korea, Japan, Taiwan, and Vietnam with high frequency. Most of the infections follow the consumptions of raw or undercooked freshwater fish, which explains its rare occurrence to childhood even in those areas mentioned earlier above. The authors have experienced it with an 8 year old boy. Abdominal ultrasonogram revealed multiple low echogenic nodules in the right lobe of liver and lymph nodes proliferation around the porta hepatis area. And abdominal C.T. scan also found multiple low attenuated nodules with delayed enhancement in liver parenchyma with hepatomegaly and multiple conglomerated lymph nodes in porta hepatis. Both abdominal ultrasonogram and C.T. scan didn't show any dilatation of peripheral intrahepatic bile ducts. In repeated stool examination, Clonorchis sinensis eggs were found in feces and the result of the skin test for Clonorchis sinensis was positive. The patient had a history of having eaten raw pond smelt back in Cheongju a month before the symptom onset. On the basis of the patient's history and the fact that Clonorchis eggs were found in feces 3 weeks after eosinophilia and symptoms were noted, the authors estimated that the findings of the patient's abdominal sonogram and C.T. scan were the radiologic findings of the acute phase of clonorchiasis, of which no report had ever been made before. So the authors report a case of clonorchiasis with atypical radiologic findings in an 8 year old boy.

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Endemicity of Zoonotic Trematode Metacercariae in Fish from Deokcheon-gang (River) in Sancheong-gun, Gyeongsangnam-do, Republic of Korea

  • Sohn, Woon-Mok;Na, Byoung-Kuk;Cho, Shin-Hyeong;Lee, Hee Il;Ju, Jung-Won;Lee, Myoung-Ro;Park, Jeong-Gil;Ahn, Jihee
    • Parasites, Hosts and Diseases
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    • v.59 no.5
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    • pp.523-529
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    • 2021
  • The endemicity of zoonotic trematode metacercariae (ZTM) was investigated with total 871 freshwater fishes (19 species) from Deokcheon-gang (a branch stream of Gyeongho-gang) in Sancheong-gun, Gyeongsangnam-do, Korea for 3 years (2018-2020). All fishes were examined with the artificial digestion method. The metacercariae of Clonorchis sinensis (CsMc) were detected in 233 (36.3%) out of 642 fish in 11 positive fish species (PFS), and their infection intensity was 27 per fish infected (PFI). Especially, in index fish, Puntungia herzi, of CsMc infection, prevalence was 64.2% and infection intensity was 37 PFI. Metagonimus spp. metacercariae (MsMc) were found in 760 (87.5%) out of 869 fish in 18 PFS and their infection intensity was 228 PFI. In sweet smelt, Plecoglossus altivelis, the prevalence of MsMc was 97.6% and their infection intensity was 3,570 PFI. Centrocestus armatus metacercariae were detected in 209 (29.4%) out of 710 fish in 8 PFS and their infection intensity was 1,361 PFI. Echinostoma spp. metacercariae were found in 293 (42.6%) out of 688 fish in 15 PFS and their infection intensity was 5 PFI. Metacercariae of Clinostomum complanatum and Metorchis orientalis were also detected in 2.7% and 21.2% fish in 4 PFS and their infection intensities were 3.1 and 3.4 PFI respectively. By the present study, it was confirmed that some species of ZTM including CsMc and MsMc are more or less prevalent in fishes from Deokcheon-gang in Sancheong-gun, Gyeongsangnam-do, Korea.

Scientific Analysis for Furnace Walls of the Joseon Dynasty Excavated in Southern Region of the Korean Peninsula (한반도 남부지역 출토 조선시대 노벽의 과학적 분석)

  • Jang, Won Jin;Han, Min Su
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.807-820
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    • 2021
  • A study on the Joseon Dynasty's furnace walls, excavated from south Korea, was conducted to identify the correlations and differences of the furnace walls found in Jeolla and Gyeongsang regions. Three ruins in the Jeolla region and two in the Gyeongsang region were selected for the analysis. The results showed a layer change depending on the degree of plasticity and difference in the number of layers and particle phase. Furthermore, although the temperature to be subjected to heat was divided into 1300℃ and 1100℃, it was not a phenomenon that appeared according to the region. Additionally, analysis result of major components revealed that the TiO2 content of most samples does not exceed 1wt%, This means that the furnace did not smelt iron sand or smelted it into low-titanium sand. This study indicated a slight similarity between the furnace walls found in the two regions, and the correlation was determined based on the nature of the ruins, raw materials of the metals ores, and composition of the raw materials constituting the furnace walls.

Assessment of fish fineness ratios passing through a fishway (어도를 통과하는 어류의 형태 체형비 평가)

  • Moon, Woon-ki;Bae, Dae-Yeul;Kim, Do-Hyun;Shin, Hyun-Beom;Suh, Jung Bin;Lim, Kyeong Hun;Lee, Eui-Haeng;Yoo, Jae-Sang;An, Kwang-Guk;Kim, Jai-Ku
    • Korean Journal of Environmental Biology
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    • v.37 no.4
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    • pp.726-734
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    • 2019
  • To understand the relationship between water velocity in a fishway and fish morphology, the fineness ratio of fish, expressed as the standard length to the body depth, was measured. The fineness ratios of fish groups belonging to Cyprinidae, Acheilognathinae, Centropomidae, and Centrachidae were relatively low. The FRs of other groups, excluding eel-shaped types of fish, were over 4.5, indicating streamlined structures. The fineness ratios of Korean fish were classified into three different types: type I was Bitterling-Carp group that favored a slow-flowing pool habitat(FRs ranged from 2.1 to 3.3), type II was the Chub group representing streamlined types (FRs FRs ranged from 3.7 to 5.2), and type III was the Smelt-Barbel fish group that preferred riffle-run habitats with high velocity (FRs is over 5.2). Fish abundance analysis of fish using the fishway during the experimental periods showed a relatively high abundance of both type II and III compared to type I. The FRs of the fish passing through fishway(velocity 0.5-1.0 m s-1) ranged from 4.5 to 5.0, indicating that the fish using the fishway were mainly the streamlined type. As one of the standard fishways in Korea, the flow rate of the ice harbor type ranged from 0.2 to 2.6 m s-1. The FR values of the fish groups using the fishway ranged from 4.3 to 5.0. In contrast, the flow rate measured in an artificial channel type of fishway (same as a natural type of fishway) ranged from 0.1 to 1.9 m s-1 and the FR values for the fish groups using a natural type of fishway ranged from 3.3 to 5.3. The low FR values in natural fish are considered to be due to differences in the flow rates between the two types of fishways.

Preservation of Fish Community by the Construction of the Tamjin Dam (탐진댐 건설에 따른 어류군집 보전방안)

  • Choi, Chung-Gil;Joh, Seong-Ju;Kim, Jong-Hae;Kim, Dong-Sup
    • Korean Journal of Ecology and Environment
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    • v.35 no.3 s.99
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    • pp.237-246
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    • 2002
  • Tamjin Dam is built in the upper reaches of the Tamjin River which flows through the Janghung-gun and Gangjin-gun of the Jeollanamdo, Korea. In order to map out a preservation strategy of the fish community from dam construction, We studied the distribution of fish distribution and changes of the habitat environment. we found 49 fish species inhabiting in the downstream and upstream of the Tamjin Dam. Among them, migratory fish were two species sweet smelt, Plecoglossus altivelis and freshwater eel, Anguilla japonica. The Coreoperca kawamebari which designated as a species to be protected by The Ministry of Environment of Korea was also observed. After the dam construction, reservoir would be filled with water and running water system will change to standing water system. Then the habitat and spawning space for mountain torrent fish will be reduced and the migration of migratory fish to upstream will be blocked. Through our study, we proposed several ways to protect fish community. In order to preserve the reduced habitat and spawning area of mountain torrent fish, a fishway has been diagnosed to be built in the shallow reservoir in the entrance of the upriver. The establishment of artificial spawning ground on the riverside has been recommended. In addition, We propose a creation of a shelter for fresh water eel, Anguilla japonica in areas where the depth of the water is about l0m by laying rocks. Since it is difficult for a spawning ground to be formed naturally in the reservoir due to the year-round changes in water level, We suggested a floating spawning facility using an artificial fixture. In the downstream of the dam, a waterway-style habitat and spawning ground in the river and increasing the diversity and abundance of fish fauna in the Tamjin River. A low-cost and highly efficient operational fishway has been recommended so that migratory fish such as Plecoglossus altivelis (sweetfish) can migrate from the lower reaches to the upper reaches of the river.