• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.141-148
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• 1987

Circulating antigens in rats experimentally infected with Paragonimus westermani were examined by ELISA. From a total of 22 albino rats, each fed with 25 metacercariae, blood samples were collected until 12 weeks after infection. The specific antibodies against P. westermani in the serum of an infected cat were purified by ammonium sulfate precipitation, DEAE anion-exchange chromatography and affinity chromatography serially. So-called double antibody sandwich ELISA method was used for the detection of circulating antigens. The results were as follows: Mean value of O.D. in control sera was O. 04 (S.D.=0. 04). After infection, mean O.D.(S.D.) values were changed serially: 0.03(0.01) at 0.5 week(3 days), 0.55(0.50) at 1 week, 0.69(0.45) at 1.5 week, O.20 (0.19) at 2 weeks and O.13(0.10) at 2.5 weeks of infection. They returned, thereafter, to the level before infection. When O. 16 (mean+3 S.D.) were considered as cut-off value, those higher than O. 16 were observed only in the sera collected between 1 and 2.5 weeks after infection. Average 8. 4 immature worms (2.2 from the lungs and pleural cavities; 6.2 from muscles) were recovered in a rat at 12 weeks after infection. The fact that circulating antigens were not detected after 3 weeks of infection was considered to the caused by the formation of antigen-antibady complexs.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.397-402
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• 1991

Paragonimus westermani is a common fluke in Korea. The present study aimed to determine serum total IgE and specific IgG levels in experimental paragonimiasis of rats. Each Wistar rat was inoculated orally with 20~25 metacercariae of P. westermani from Cambaroides similis. Before and after infection(1,2,3,4,6,8 weeks) of P. westermani, the blood was collected from the retro- orbital venous plexus of rats and kept serum at $-70^{\circ}C$. Serum total IgE and specific IgG levels were determined by the capture and conventional enzyme-linked immunosorbent assay, respectively. The results were as follows; 1. Serum IgE values were increased to 0. 18${\pm}$0.042 at 2 weeks, $0.28{\pm}0.151$ at 4 weeks and 0.43${\pm}0.055$ at 8 weeks after infection. The absorbances of non-infected rats ranged $0.07{\pm}0.021~0.12{\pm}0.025$. 2. Specific IgG values were slightly increased at 3 weeks ($0.20{\pm}$0.032) and gradually increased up to 8 weeks($0.31{\pm}0.067$) after infection. The absorbances of non-infected rats ranged $0.11{\pm}0.035~0.18{\pm}0.019$. The present results suggested that p. westermani could elevate serum IgE and specific IgG antibodies in Wistar rats which were not a good definitive host.

• Resources Recycling
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• v.29 no.4
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• pp.67-72
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• 2020

Recycling processes of spent copper wires cosisnt of several steps of cutting and chopping processes for peeling covering materials followed by gravity separation processes, where copper is recovered. Because copper thin wires could be lost during further recycling processes, the wire may need to be further treated. In the present study, the copper thin wire was treated with ball milling to prevent the loss. Since the aggregation of the copper wire could be formed by bending and entangling the copper wire each other, the degree of flexion of the copper wire was measured after ball milling. When the 0.5 cm and 3 cm copper wires were used, the 0.5 cm copper wire was not bent and the 3 cm copper wires were aggregated regardless of the ball addition. When the 1 cm and 2 cm copper wires were used, the degree of flexion was remarkable when the balls were added. In the tests using 2 cm copper wires, the aggregation ratio of the copper wire gradually increased with the amount of the 20 mm alumina ball, and when 200 ml of 30 mm alumina ball was used, the aggregation ratio increased to 89.29 %, but after increasing the ball amount further, the aggregation ratio decreased. Thus, it is expected that the loss of the copper wire could be reducedif when the copper thin wire is treated with ball milling by the aggregation of copper thin wires.

• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.27-36
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• 1997

초기후두암에 있어서 보존적 술식의 장점은 후두 전적출술시와 같은 국소치료효과를 얻을 수 있으면서도 후두의 생리적 기능을 최대한 보존하는데 있다. 성공적인 후두부분절제술을 위해서는 후두내에서 종양의 발생위치 및 그 확산에 대한 연부조직들의 해부학적 역할에 대한 이해가 필요하다. 과거에는 초기후두암환자에서 정상적인 목소리를 보존할 수 있다는 이점 때문에 방사선 치료가 일차적 치료요법으로 많이 시행되어 왔다. Wang 과 Wong은 성대 막양부에 국한된 병변에서 방사선치료에 대한 5년간 조절율(5-year control rate)이 92%, 전연합부를 침범한 경우가 81%, 그리고 후방으로 전파된 경우 76%로 감소된다고 보고하였다. Olofsson 등은 전연합부를 침범한 57례의 환자에서 방사선 치료를 시행하여 85.7%의 5년 생존율을 얻었으나, 57례중 15례에서 재발하여 구제수술(salvage surgery)을 시행하였고, Jesse 등$^{13)}$ 은 전연합부를 침범한 91례의 T1, T2 성문암을 방사선 치료를 시행하여 8.8%의 실패율을 보였으나 22례의 환자에서 재발하여 후에 salvage surgery를 시행하였다. 그러나 Ogura 등은 피열 연골을 침범한 79례의 환자에서 보존적 수술을 시행한 결과 6례의 환자에서 재발하여 90%의 3-years control rate를 얻을 수 있었다고 보고하였다. 이처럼 병변이 전연합부, 피열연골 혹은 후방성문하부로의 침범이 있는 경우는 방사선 치료 효과가 떨어지고, 따라서 방사선 치료에 실패할 가능성이 보다 높기 때문에 비록 방사선 치료 후 실패한 경우에서 구제 수술을 시행할 수는 있지만 후두기능을 보존하려는 궁극적인 목표를 생각할 때 보존적 수술을 우선적으로 시행하는 것이 바람직하다고 할 수 있다. Biller 등은 방사선 요법에서 실패한 성문부 종양에서는 대부분 전적출술을 시행하지만 일부는 보존적 수술을 시행할 수 있다고 보고하였다. 이들은 반대측 성문부에 종양의 침범이 없어야 하고, 전연 합으로의 파급은 있어도 가능하며 성대돌기를 제외한 피열연골이 정상이어야 하고, 종양의 성문하부로의 파급이 5mm 이내라야 하며, 연골에 침범이 없어야 하고, 성대고정이 없어야 하며, 재발 병소가 방사선요법 전의 원발병소와 상관관계가 있어야 하며, 원발병소가 후두부분적출술에 합당할 경우 보존적 술식을 시행할 수 있다고 하였다. 최근에는 다양한 후두 재건술의 발달로 보다 진행된 후두암에 대한 보존적 후두절제술들이 소개되고 있다. 단측 T3,T4 후두암 혹은 경성문암, 이상와에 위치한 암의 경우 음성만을 재건하는 후두근적출술 (near total laryngectomy)을 시행하기도 한다. 본원 이비인후과에서 1986년부터 초기성문암 51례 중 24례(47.1%)와 초기성문상암 17례 중 12례 (70.6%)에 대하여 보존적 술식을 시행하였다. 초기 성문암의 보존적 술식을 시행한 24례중, 2례(8.3%)에서 경부재발, 1례(4.2%)에서 경부재발과 동반된 폐의 원격전이가 있었으나 원발부위의 재발은 관찰되지 않았고, 술후 합병증으로 1례(4.2%)에서 후두협착, 3례(12.5%)에서 수술부위의 육아종형성, 그리고 1례(4.2%)에서 기관지염이 발생하였으나 오연으로 인한 폐렴은 발생하지 않았다. 초기성문 상암의 보존적 술식을 시행한 12례 중 1례(8.3%)에서 원발병소의 재발, 2례(16.7%)에서 경부재발이 있었으며, 술후 합병증으로 3례(16.7%)에서 오연으로 인한 폐렴의 발생이 있었지만 다른 합병증은 발생하지 않았다. 초기성문암 24례 중 재발이 나타난 3례의 환자를 제외한 21례(97.5%)와 초기성문상암 12례 중 재발이 나타난 3례의 환자를 제외한 9례 (75%)에서는 현재까지 재발소견을 보이지 않고 있다. 이러한 결과는 다른 보고자들과 유사한 결과를 보이고 있지만 아직까지 증례가 많지 않기 때문에 생존율을 얻기에는 미흡한 점이 있으며, 향후 지속적인 추적관찰이 필요할 것으로 사료된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.399-404
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• 2021

From 1 January 2020, the limit for Sulphur in fuel oil used on board ships operating outside designated emission control areas will be reduced to 0.5 %. This regulation by international maritime organization (IMO) is able to significantly reduce the amount of Sulphur oxides (SOx) discharging from ships and should have environmental advantages and health for all over the world. To meet the regulation, in these days, wet scrubber system is being actively developed. However, this process leads to make washing wastewater. In this study, we evaluated ion exchange resin system in accordance with scrubber wastewater discharge regulation by IMO. Theoretical wastewater used as feed solution of lab scale water treatment systems. The results revealed that nitrate ion was removed selectively in spite of high TDS wash wastewater solution depending on ion exchange resin property. Moreover, it was possible to improve efficiency of the system by optimizing operating conditions.

• Clean Technology
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• v.27 no.3
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• pp.240-246
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• 2021

The waste etching solution for chip on film (COF) contained about 3.5% copper, and it was recovered through cementation using iron samples. The effect of cementation with plate, chip, and powder iron samples was investigated. The molar ratio (m/r) of iron to copper was used as a variable in order to increase the recovery rate of copper. As the molar ratio increased, the copper content in the solution rapidly decreased at the beginning of the cementation reaction. Before and after the reaction, the copper content of the solution was determined by Inductively Coupled Plasma (ICP) using copper concentration according to time. After cementation at room temperature for 1 hour, the recovery rate of copper had increased the most in the iron powder sample, having the largest specific surface area of the samples, followed by the chip and plate samples. The recovered copper powder was characterized for its crystalline phase, morphology, and elemental composition by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS), respectively. Copper and unreacted iron were present together in the iron powder samples. The optimum condition for recovering copper was obtained using iron chips with a molar ratio of iron to copper of 4 giving a recovery rate of about 98.4%.

• Journal of Ginseng Culture
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• v.3
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• pp.119-131
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• 2021

The purpose of this study was to explore the characteristics of and solution to thermogenic reactions to Korean ginseng through bibliographic research. A review of bibliography on the thermogenic reaction induced by ginseng indicated that people who lack fluids, have fever in lungs, a stuffy chest, coughing up sputum, a strong pulse, and constipation due to fever in the stomach may exhibit such a reaction. In the herbal medicine book of the Qing Dynasty, Bon-Cho-Jeong-Ui (本草正義) recorded that wild simulated ginseng is slightly cold and replenishes the body's liquid reserves. The book also describes the field cultivated ginseng is slightly warm and enhancing stamina. Bon-Kyung-Bong-Won (本經逢源), Bon-Cho-Pyon-Dok (本草便讀), and Bon-Cho-Jeong-Ui were published authors in the Qing Dynasty, and they explained that ginseng fine root is bitter, supplements bodily fluids, and can be easily ingested because it is cold. Wol-Ji-In-Sam-Jeon (月池人蔘傳) and Bon-Cho-Bi-Yo (本草備要) described fresh ginseng assweet, bitter, and slightly cold in the Ming and Qing Dynasties, respectively. On the basis of this bibliographic description, the thermogenic reaction induced by Korean ginseng can be overcome by using ginseng fine root, fresh ginseng, or wild simulated ginseng. These ginseng radices are slightly cool, replenish human bodily fluids, and show the physiological effects of easy ingestion properties.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.605-612
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• 2021

Amid growing global damage due to abnormal weather caused by global warming, the introduction of eco-friendly cars is accelerating to reduce greenhouse gas emissions from internal combustion engines. Accordingly, many studies are being conducted in each country to prepare for the explosion of hydrogen fuel in semi-closed spaces such as tunnels and underground parking lots to ensure the safety of hydrogen-electric vehicles. As a result of predicting the explosion pressure of the hydrogen tank using the equivalent TNT model, it was found to be about 1.12 times and 2.30 times higher at a height of 1.5 meters, respectively, based on the case of 52 liters of hydrogen capacity. A review of the impact on the human body and buildings by converting the predicted maximum explosive pressure into the amount of impact predicted that all predicted values would result in lung damage or severe partial destruction. The predicted degree of damage was applied only by converting the amount of impact caused by the explosion, and considering the additional damage caused by the explosion, it is believed that the actual damage will increase further and safety and disaster prevention measures should be taken.

• Clean Technology
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• v.29 no.4
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• pp.262-271
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• 2023

Globally, the amount of waste plastics has been occurring to environmental problems. As a result, it is necessary to research methods that utilize waste plastic pyrolysis oil (WPPO) produced by pyrolysis. One such method being studied is utilizing WPPO as a naphtha feedstock. In this study, five types of WPPO were analyzed to determine whether they can be used as raw materials for naphtha. Because of their wide boiling point range, the WPPOs were fractionated into light and heavy fractions through vacuum distillation, and the separation and purification techniques were analyzed using GC-VUV to determine the content of paraffin, olefin, and other compounds. All WPPOs showed high olefin content regardless of the source and fraction. Aromatic and paraffin content varied depending on the source, and oxygen and other compounds also varied significantly by source and fraction. In addition, the light fraction showed a carbon distribution similar to that of naphtha, whereas the heavy fraction showed a carbon distribution of C₁₁ ~ C₁₄. In conclusion, additional processes and raw material selection are required to utilize waste plastic pyrolysis oil as a raw material for naphtha.

• Clean Technology
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• v.30 no.2
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• pp.105-112
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• 2024

Globally, the demand for electric vehicles has surged due to greenhouse gas regulations related to climate change, leading to an increase in the production of used batteries as a consequence of the battery life issue. This study aims to selectively leach and recover valuable metal lithium from the cathode material of spent LFP (LiFePO₄) batteries among lithium-ion batteries. Generally, the use of inorganic acids results in the emission of toxic gases or the generation of large quantities of wastewater, causing environmental issues. To address this, research is being conducted to leach lithium using organic acids and other leaching agents. In this study, selective leaching was performed using the organic acid methane sulfonic acid (MSA, CH₃SO₃H). Experiments were conducted to determine the optimal conditions for selectively leaching lithium by varying the MSA concentration, pulp density, and hydrogen peroxide dosage. The results of this study showed that lithium was leached at approximately 100%, while iron and phosphorus components were leached at about 1%, verifying the leaching efficiency and the leaching rates of the main components under different variables.