• 한국응용과학기술학회지
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• 제28권1호
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• pp.57-63
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• 2011

Polymer electrolyte membrane fuel cell (PEMFC) performance degrades when hydrogen sulfide ($H_2S$) is present in the fuel hydrogen gas; this is referred to as $H_2S$ poisoning. This paper reveals $H_2S$ poisoning on PEMFC by measuring electrical performance of single cell FC under various operating conditions. The severity of $H_2S$ poisoning depended on $H_2S$ concentration under best operating conditions($65^{\circ}C$ of cell temperature and 100% of anode humidification). $H_2S$ adsorption occured on the surface of catalyst layer on MEA, but not on the gas diffusion layer(GDL) by analyzing SEM/EDX data. In addition, MEA poisoning by $H_2S$ was cumulative but reversible. After poisoning for less than 150 min, performance of PEMFC was recovered up to 80% by just inert nitrogen gas purging.

• Bulletin of the Korean Chemical Society
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• 제20권12호
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• pp.1413-1417
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• 1999

Chemical poisoning of Ni/MgO catalyst was induced by hot alkali carbonate vapor in molten carbonate fuel cell (MCFC), and the poisoned (or contaminated) catalyst was characterized by TPR/TPO, FTIR, and XRD analysis. Carbonate electrolytes such as K and Li were transferred to the catalyst during DIR-MCFC operation at 650 ℃. The deposition of alkali species on the catalyst consequently led to physical blocking on catalytic active sites and structural deformation by chemical poisoning. TPR/TPO analysis indicated that K species enhanced the reducibility of NiO thin film over Ni as co-catalyst, and Li species lessened the reducibility of metallic Ni by chemical reaction with MgO. FTIR analysis of the poisoned catalyst did not exhibit the characteristic ${\vector}_1$$(D_{3h})$ peaks (1055 $cm^{-1},\;1085\;cm{-1})$ for pure crystalline carbonates, instead a new peak (1120 $cm^{-1})$ was observed proportionally with deformed alkali carbonates. From XRD analysis, the oxidation of metallic Ni into $Ni_xMg_{1-x}O$ was confirmed by the peak shift of MgO with shrinking of Ni particles. Conclusively, hot alkali species induced both chemical poisoning and physical deposition on Ni/MgO catalyst in DIR-MCFC at 650 ℃.

• 한국응용과학기술학회지
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• 제28권4호
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• pp.497-501
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• 2011

Polymer electrolyte membrane fuel cell (PEMFC) performance degrade when sulfur dioxide is present in the fuel hydrogen gas, this is referred as $SO_2$ poisoning. This paper reveals $SO_2$ poisoning on PEMFC cathode part by measuring electrical performance of single cell under 1 ppm and 5 ppm on $SO_2$ gas operating. The security of $SO_2$ poisoning depended on $SO_2$ concentration under the best operating conditions($65^{\circ}C$ of cell temperature and 100% of relative humidity between anode and cathode). $SO_2$ adsorption occured on the surface of catalyst layer on membrane electrode assembly (MEA), In addition, MEA poisoning by $SO_2$ was cumulative but reversible. After poisoning within 5 ppm $SO_2$ for 1hr, the electrical performance of PEMFC was found to recover up to about 93% by cyclic voltametry scan.

• Journal of Oral Medicine and Pain
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• 제9권1호
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• pp.147-156
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• 1984

In spite of the radical increase of chemical poisoning cases caused by prevalent of oranic chlorine like endosulfan, the study of detection of chemical poisoning has seldom been attempted; the study of poisoning in teeth, which is more secure physiochemically, and in all the oral tissues has been even less attempted. The author has administered endosulfan into the month of a rabbit, causing its death, and tried to detect endosulfan in the teeth, jaws, and oral tissues through forensic chemical and histopathological tests. The result obtained is as follows : 1. By thin layer chromatography, endosulfan was detected in the jews, dental hard tissues, dental pulp, blood, and the liver. 2. By gas chromatography, it was also detected in the jaws, dental hard tissues, dental pulp, blood, and the liver. 3. The congestion and hemorrhage in buccal mucosa, palatal mucosa, and dental pulp was detected.

• 한국환경보건학회지
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• 제46권5호
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• pp.565-575
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• 2020

Objective: South Korea still lacks systematic national poisoning data collection or a poison control center (PC). The objectives of this study are to provide estimates of poisoning incidents in South Korea and to stress the necessity of a national poisoning surveillance framework managed by a national PC. Method: The number of poisoning incidents was estimated based on the 2018 annual report of the American Association of Poison Control Centers' National Poison Data System (NPDS). Our estimation of poisoning data was classified according to age group, reason for poison exposure, and case management site. Results: Total poisoning cases estimated numbered 326,636, which is tantamount to 631 cases per 100 thousand. Poisoning cases among those younger than five years old accounted for 71.7% in the United States. Fatal poisoning cases were estimated to be 210.63 (95% CI: 199.70-222.15). Non-intentional poisoning cases (250,378 cases, 95% CI: 249,992-250,764, 76.7%) were estimated to be far higher than intentional cases (62,399 cases, 95% CI: 62,207-62,593, 19.1%). Conclusion: Our results can be used to suggest the necessity of producing national poisoning data and establishing a PC despite the uncertainty of estimation.

• Korean Chemical Engineering Research
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• 제51권3호
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• pp.370-375
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• 2013

상업용 막전극접합체를 사용하여 제작한 고분자전해질 연료전지의 CO poisoning 및 air bleeding 효과가 스택의 셀전압 성능에 미치는 영향을 분석하였다. 실험을 통해 확보한 동적 응답 데이터에 일차 미분방정식으로 표현되는 일차계 모델을 적용하여 정상상태 이득과 시간상수를 계산하는 방법으로 스택 셀전압의 응답 특성을 정량화하였다. 연료전지 개질기로부터 공급되는 개질 가스에 포함된 CO 농도가 1 ppm 증가할 때마다 셀전압은 1.3~1.6 mV 저하되고, CO 농도의 변화폭이 클수록 정상상태에 도달하기까지 걸리는 시간이 점점 짧아지는 것으로 분석되었다. CO poisoning에 의해 저하된 스택 성능을 회복시키기 위해 air bleeding을 수행할 경우, 주입하는 공기의 농도를 증가시킬수록 셀전압 상승폭(정상상태 이득)이 커지고 회복시간(시간상수)은 짧아지나, 1% 수준의 air bleeding만으로도 CO poisoning이 일어나기 전 셀전압의 87%~96%를 1~30 min 이내에 회복시킬 수 있는 것으로 분석되었다.

• 대한임상독성학회지
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• 제8권2호
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• pp.61-68
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• 2010

Purpose: Poisoning is a major health problem for the elderly, and poisoning can cause fatal side effects. However, the characteristics and clinical features of elderly patients with acute poisoning have not been well studied in the previous domestic research. So, we tried to analyze the clinical characteristics and toxic substances of the patients who were 65 years old or older and who were admitted to the regional emergency medical center due to acute poisoning. Methods: We retrospectively reviewed the medical records and poisoning protocols of the patients who were 65 years of age or older and who had with acute poisoning and who visited the ED in our emergency center from January 2005 to December 2009. We collected the demographic information, the gender, the underlying diseases, the causes and toxic substances, the initial presentation, the treatment and the outcomes. Results: A total of 2179 poisoned patients visited the hospital during 5 years, and among them 244 were 65 years of age or older (11.2%). The mean age was $75.6{\pm}6.9$ years and the male:female ratio was 1:1.7. The most common cause of poisoning was suicide (73.4%) and the most common source of poisonous substances was their own drugs. Of the substances used for poisoning, benzodiazepine was the most common drug (25.8%), followed by sedatives other than benzodiazepine (25.4%), insecticide (12.7%), chemical agents (12.3%) and herbicides (8.2%). The most common initial presentation was mental change (64.8%). When comparing the factors between the three elderly groups, there was no difference in gender, the cause, the substances and the underlying disease. The outcomes of treatment included ICU admission (56.1%), a good condition at discharge (12.7%) and admission to a general ward (12.7%). The overall mortality rate was 10.2% for the elderly patients. Conclusion: In this Korean study, unlike the foreign studies, the most common cause of poisoning in elderly patients was intentional poisoning. The admission rate was 68.8% and mortality rate was 10.2%.

• Food Science and Biotechnology
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• 제18권3호
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• pp.594-603
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• 2009

The genus Bacillus includes a variety of diverse bacterial species, which are widespread throughout the environment due to their ubiquitous nature. A well-known member of the genus, Bacillus cereus, is a food poisoning bacterium causing both emetic and diarrhoeal disease. Other Bacillus species, particularly B. subtilis, B. licheniformis, B. pumilus, and B. thuringiensis, have also recently been recognized as causative agents of food poisoning. However, reviews and research pertaining to bacilli have focused on B. cereus. Here, we review the literature regarding the potentially toxigenic Bacillus species and the toxins produced that are associated with food poisoning.

• 한국화재소방학회논문지
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• 제32권2호
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• pp.118-129
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• 2018

본 연구는 산업재해예방기관인 안전보건공단(KOSHA)에서 실시한 소화약제 중독 질식 재해사례분석을 통해 소화 약제를 포함한 화학물질의 안전한 취급방안을 제안하기 위함이다. 산업재해통계에 따르면 2011~2016년 산업현장에서 발생한 화학물질 중독 질식재해는 해마다 증가 및 다 변화 양상을 보여주고 있다. 일반 사고성재해와 달리 화학물질 재해는 재해강도가 크고 화학물질 위험성 정보 확인이 어려운 특징이 있다. 화학물질 재해의 예방을 위해서는 화학물질 취급 전 위험성을 평가하는 것이 무엇보다 중요하다. 본 논문은 유해위험성인지와 위험성평가가 어려운 화학물질의 안전한 사용을 위해 안전보건공단에서 개발한 화학물질 필수정보 확인 프로세스(CHEM-i)와 화학물질위험성평가기법(CHARM)의 활용방안을 제시하고자 한다.

• 공업화학
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• 제31권3호
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• pp.299-304
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• 2020

나노입자는 많은 화학합성에서 중요한 촉매역할을 한다. 촉매로 이용되는 나노입자를 합성할 때 colloidal synthesis를 많이 활용하고 있다. Colloidal synthesis를 이용해 나노입자를 합성할 경우 환원제, capping agent, shape directing agent 등이 촉매에 surface poisoning을 일으켜 촉매의 특성이 낮아질 수 있으며 합성 및 분리 과정 중 유해폐기물의 발생한다. Colloidal synthesis에서 사용되는 첨가제들의 양을 줄여 합성할 수 있는 새로운 나노입자를 합성법을 개발하여 은나노입자를 합성하였다. 결정화 기술을 이용하여 환원제, capping agent의 양을 줄일 수 있고 더욱이 합성된 나노입자 표면의 흡착되는 물질의 양을 줄여 surface poisoning을 낮출 수 있었다. 환원제로는 단당류와 이당류를 이용하여 surface poisoning이 거의 없는 은 나노입자는 resazurin의 산화환원 반응의 촉매로 이용할 수 있어 은 나노입자를 이용한 촉매 반응의 메커니즘을 분석하였다.