• Clean Technology
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• v.14 no.1
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• pp.61-68
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• 2008

There have been great attentions on polymer electrolyte membrane fuel cell (PEMFC) due to their advantageous characteristics such as zero emission of hazardous pollutant and high energy density. In this work, we evaluated degradation phenomena and stability of single cell performance via one dimensional single cell modeling. Here, CO poisoning on anode on anode was considered for cell performance degradation. Modeling results showed that the performance and stability were highly degraded with CO concentration in fuel gas. In addition, cell performance was reduced by slow oxygen reduction on cathode in long term operation. In order to overcome, it is required to increase ratio o#hydrogen in the fuel gas of anode and high Pt loading contained in the cathodic catalyst layer.

• Korean Journal of Health Education and Promotion
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• v.6 no.1
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• pp.66-74
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• 1989

The purpose of this study was to determine appropriate training content and methods for a health educational program for rural people by analysing data collected through a structured interview survey with the rural people of Kangwha county in June, 1987, The variables analyzed for the educational content were the diseases of greatest concern and the most urgent health problems, and for the educational methods, the health educator, place of education and types of educational media were analyzed. The results are as follows: 1. The disease of greatest concerned was gastroenteritis(22.6%), followed by diabetes(13.7%), and hepatitis (10.2%). The respondents with old age and less education were more concerned with arthritis, and those with higher education were more concerned with diabetes. 2. The most urgent health problem was agricultural chemical poisoning(46%), followed by smoking(12.8%), and the lack of balance between meals and nutrition(8.8%). The people with less education and with higher income were less concerned with agricultural chemical poisoning and smoking. 3. Of the respondents, 77.4% wanted to be educated by physicians and the village auditorium was the most preferred place of education. Education in a lecture format was desired by 36.3% of respondents. Personal counselling was more preferred by old and less educated people, and people with higher education preferred printed matters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.325-331
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• 2007

In this study, the inter-metal dielectric material of FSG was changed by low-k material in $0.13{\mu}m$ foundry-compatible technology (FCT) device process based on fluorinated silicate glass (FSG). Black diamond (BD) was used as a low-k material with a dielectric constant of 2.95 for optimization and yield-improvement of the low-k based device process. For yield-improvement in low-k based device process, some problems such as photoresist (PR) poisoning, damage of low-k in etch/ash/cleaning process, and chemical mechanical planarization (CMP) delamination must be solved. The PR poisoning was not observed in BD based device. The pressure in CMP process decreased to 2.8 psi to remove the CMP delamination for Cu-CMP and USG-CMP. $H_2O$ ashing process was selected instead of $O_2$ ashing process due to the lowest condition of low-k damage. NE14 cleaning after ashing process lot the removal of organic residues in vias and trenches was employed for wet process instead of dilute HF (DHF) process. The similar-state of SRAM yield was obtained in Cu/low-k process compared with the conventional $0.13{\mu}m$ FCT device by the optimization of these process conditions.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.102-107
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• 2012

The recovery of a Pt anode in a PEMFC through 30 ppm $H_2S/H_2$ exposure was evaluated by using a cyclic voltametry(CV) scan. First, the PEMFC unit cell performanc loss was measured three times under an anode feeding with 30 ppm $H_2S/H_2$ for 1hr at $0.5A/cm^2$ of current density. The initial cell performance was $1.16A/cm^2$ at 0.6 V without $H_2S$ poisoning. After first poisoning step for 1hr the cell performance was decrease to $0.77A/cm^2$, and the further poisoning steps decreased up 0.57 V. Finally, the recovery of the cell performance of $H_2S$ poisoned PEMFC was achieved up to 90.3% by applying CV scan. Moreover, we also found out that another possible approach for over 80% recovery of the cell performance of $H_2S$ poisoned anode Pt catalyst layer was to just inject fresh hydrogen into the anode feeding stream.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.639-642
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• 2000

Chemical facility system have dangerous elements that can injure the human like an explosion and a fire, gas poisoning by a leakage of the harmful chemical material. In addition to a vibration of the machine occurs the leakage. Therefore, the chemical factory requires for periodic monitoring of the vibration. But, until now, the operator has executed a monitoring of the machine by the senses. So, the diagnostic expert system by which the operator can judge easily and expertly a condition of the machine is developed. This paper describes the structure of diagnostic system and the diagnostic algorithm using fuzzy inference

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.391-394
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• 2002

Berberine and berberrubine, which display antitumor activity, have also demonstrated distinct enzyme-poisoning activities by stabilizing topoisomerase Ⅱ-DNA cleavable complexes. The protoberberine berberrubine differs in chemical structure with berberine at only one position, however, it shows a prominent activity difference from berberine. Solution structures of berberine and berberrubine determined by NMR spectroscopy are similar, however, the minor structural rearrangement has been observed near 19 methoxy or hydroxyl group. We suggest that the DNA cleavage activities of topoisomerase Ⅱ poisons could be correlated with both chemical environments and minor structural change together with hydrophobicity of interacting side chains of drugs with DNA molecule.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.230-239
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• 2018

Objective: The purpose of this study is to identify the kinds and exposure levels of health hazards in the metalworking process in relation to acute poisoning accidents caused by methanol in 2016. Methods: The number of industries, workplaces, exposed workers, regional distribution, and exposure level of health hazards in metalworking process were investigated based on employee exposure assessment database provided by KOSHA (the Korea Occupational Safety and Health Agency), which was collected from workplace hazard evaluation programs in Korea. Exposure metrics for methanol were assessed by RCR (risk characterization ratio). Results: The numbers of processes, workplaces, and exposed workers of metalworking, which include CNC (computer numerical control) were 25, 14,405, and 169,102 respectively. The numbers of samples of chemical hazards including methanol were 91,325, and it was found that workers in metalworking were exposed to 249 kinds of chemical hazards. There were 16 kinds of special controlled substances including beryllium. It is estimated that the number of workplaces involving CNC process was 2,537, and the number of exposed workers was 27,976. In CNC process, the total number of workplaces handling methanol was 36, and 298 workers were estimated to be exposed. There was no exceeded that surpassed the OEL and 49% of samples were below the limit of detection. Methanol exposure concentrations in Gyeonggido Province were statistically significantly higher than in other areas (p <0.0001). Conclusions: In the metalworking process including CNC, there is exposure to a wide variety of health hazards. There was no sample exceeding the OEL for methanol. Therefore, it is necessary to recognize the limits of the employee exposure assessment system and urgently improve measures to prevent the occurrence of events like methanol poisoning.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.27-38
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• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Journal of Sensor Science and Technology
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• v.25 no.3
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• pp.161-172
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• 2016

The use of a chemical sensor array can help discriminate between chemicals when comparing one sample with another. The ability to classify pattern characteristics from relatively small pieces of information has led to growing interest in methods of sensor recognition. A variety of pattern recognition algorithms, including the adaptive radial basis function network (RBFN), may be applicable to gas and/ or odor classification. In this paper, we provide a broad review of approaches for various types of gas and/or odor identification techniques based on RBFN and drift compensation techniques caused by sensor poisoning and aging.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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• pp.83-89
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• 2004

Acute poisoning is one of the diseases which need the most fastest emergency measures at the very beginning. However, at present, The Korea doesn't manage the toxication all over the country, and in particular, there is no guide to medical cure paying due regard to the traits of each area. This paper focused on the issue that the necessary data in preparing the facilities for the treatment of the poisoned patients and materials for medical treatment including antidote would have to be collected, after finding the special features of the symptoms by searching the present conditions of the poisoning in small towns next to farm villages in the North area of Youngseo, Kangwon province. This study was based on the questionnaires from 111 patients who were carried into the emergency room by the poisoning in two university hospitals of the North area of Youngseo, Kangwon, for one year, 2002. Upon investigation, the patients(111) visiting emergency room by the acute poisoning during the research period was found to be 0.37 percent of all patients(30,085) visiting emergency room. Among them, the most high percentage was given in their twenties and thirties at the rate of $39.6\%$, and the ratio($40.5\%$) of the poisoned patients after their fifties was much higher than a research($10\%$) of other areas. Many poisoned patients came to their rescue in an emergency room generally in spring and in winter, from 7 a.m. to 3 p.m. Agricultural chemical of the toxic materials had a majority at a ratio of $57.7\%$, and paraquat of the agricultural chemicals was found to have a lot of toxicity by $31.7\%$. As the trace of the toxication, the oral poisoning was common by $89.2\%$, and $55.9\%$ in the case of operating gastric lavage and nasogastric irrigation, but only $14.4\%$ for prescribing antidote. The mortality of the acute poisoned patients was $17.2\%$, and the toxication by paraquat held a majority. As a result, the acute poisoning of the North area in Youngseo, Kangwon had both of the characteristics of the rural and the city, and the patients over their fifties by the population aging had more attack of the disease than other regions. Also, with the high ratio of the toxication by the agricultural chemicals, especially, the lethal agricultural chemical was used frequently. Therefore, these dangerous situations need to find the ways to cope with.