• 대한임상독성학회지
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• 제4권2호
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• pp.122-127
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• 2006

Purpose: It is not easy to detect carbon monoxide (CO) leakage, and CO-intoxicated patients do not show a specific set of symptoms. The aims of this study are to clinically evaluate patients with CO gas intoxication from a CO leak at an underground shopping center, and to discuss the establishment of a disaster prevention plan. Methods: A total of 51 patients intoxicated by CO gas exposure in a gas disaster at a underground shopping center in Seoul on September 8, 2006 were enrolled in this study, and the patients' medical records were retrospectively reviewed. Results: The mean patient age was $29.4{\pm}6.3$. The initial mean COHb level was $14.98{\pm}6.97%$. The number of patients with COHb greater than 25% was three, and six patients experienced a syncopal attack. Only one patient-was treated with hyperbaric oxygen therapy. However, none of the patients complained of severe neurologic or cardiovascular symptoms. Conclusion: The symptoms of CO intoxication are non-specific and difficult to define, and the detection of CO leak-age is difficult. Thus, workplaces should be equipped with leakage sensors and automatic alarm systems and should have develop disaster prevention plans.

• 한국재료학회지
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• 제28권6호
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• pp.365-369
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• 2018

We perform density functional theory calculations to study the CO and $O_2$ adsorption chemistry of Pt@X core@shell bimetallic nanoparticles (X = Pd, Rh, Ru, Au, or Ag). To prevent CO-poisoning of Pt nanoparticles, we introduce a Pt@X core-shell nanoparticle model that is composed of exposed surface sites of Pt and facets of X alloying element. We find that Pt@Pd, Pt@Rh, Pt@Ru, and Pt@Ag nanoparticles spatially bind CO and $O_2$, separately, on Pt and X, respectively. Particularly, Pt@Ag nanoparticles show the most well-balanced CO and $O_2$ binding energy values, which are required for facile CO oxidation. On the other hand, the $O_2$ binding energies of Pt@Pd, Pt@Ru, and Pt@Rh nanoparticles are too strong to catalyze further CO oxidation because of the strong oxygen affinity of Pd, Ru, and Rh. The Au shell of Pt@Au nanoparticles preferentially bond CO rather than $O_2$. From a catalysis design perspective, we believe that Pt@Ag is a better-performing Pt-based CO-tolerant CO oxidation catalyst.

• 한국식품저장유통학회지
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• 제7권2호
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• pp.177-183
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• 2000

A supercritical fluid extraction was performed for the extraction of phenolics from grape seeds which up to now have been discarded. The optimum condition for extraction process was predicted through response surface methodology using central composit experimental design. The extraction amount of grape seed phenolics was increased by increasing extraction temperature, pressure, and concentration of co-solvent (ethanol). The optimum extraction conditions were 84.83$^{\circ}$C, 51.50MPa and 1.27% ethanol. The yield of phenolics using SFE was higher with 3 folds than ethanol and 4 folds than hexane but less than 80% methanol. In the respects of food poisoning, the approved solvents were restricted to ethanol and hexane. So, SFE for extraction of phenolics could be powerful alternative method for solvent extraction.

• Journal of Preventive Medicine and Public Health
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• 제6권1호
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• pp.71-76
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• 1973

1) The oxygen consumption was studied with albino rats under normal environment after they were given Cytochrome C intravenously (10mg/kg). The cosumption was 74.6cc/kg min. with that of control, 75.4cc/kg. min. The difference of the consumptions was not statistically significant. However, under 0.5% CO environment, the oxygen consumption of the Cytochrome C treated rats (62.5cc/kg min) was significantly greater than the control (42.1cc/kg min.) 2) The recovery time of rat acutely poisoned by 1% CO was studied. The recovery time of the Cytochrome C treated group was 37.2 minutes and in control group it was 52.2 minutes. Also significant difference of fatality was noted between the treated group (21.8%) and the untreated group (49.7%) 3) The combined effects of the hyperbaric oxygenation (100% $O_2$ at 3 atmospheric pressures) and the Cytochrome C administration was compared with the effect of the simple hyperbaric oxygenation. There was no significant difference of recovery time between the experimental group while the fatality of the experiment group was lower than control group.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.92-100
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• 2000

The model gas reaction tests were carried out to investigate the purification characteristics of methane on the exclusive catalyst for NGV. The experiment was conducted with the factors which affect the conversion efficiency of methane, such as Redox ratio, coexistence components of CO, MO, $H_2$O, precious metals and additives. The catalyst loaded with larger amount of pd and with additive La showed lower light-off temperature. In the presence of CO and NO, the conversion efficiency of methane was varied according to the kind of additive loaded. The conversion efficiency of methane was dropped for the catalyst loaded with La under lean air-fuel ratio, while it increased for the one loaded with Ti+Zr for the same condition. It was shown that the water vapor inhibited methane from oxidation by its poisoning on the surface of catalyst.

• 대한환경공학회지
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• 제32권3호
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• pp.248-255
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• 2010

본 연구는 연안해역에서 발생하는 적조의 현장 제어기술로 전자빔을 이용하고자 적조사멸에 대한 전자빔 조사의 효율성을 평가하였다. Prorocentrum minimum, Prorocentrum micans, Cochlodinium polykrikoides, Heterosigma akashiwo, Alexnadrium catenella의 5종을 실험대상 적조로 선정하여 배양하였으며, 실제 경남 통영(2007. 8. 15)에서 발생한 적조에 대해서도 동일한 실험을 수행하였다. 전자빔 조사선량은 1 kGy, 2 kGy, 4 kGy, 8 kGy로 1 kGy의 전자빔 조사로 50~65%의 적조사멸율을 보였으며, 1일 경과 시 86~97% 사멸하였다. Chlorophyll-a의 경우 조사 즉시 50~64% 감소하고, 1일 경과한 뒤 72~93%의 감소율을 보였다. 또한 전자빔 조사 즉시 S-protein은 28~47%, S-carbohydrate는 16~45% 가 증가하였으며, 1일의 시간 경과 후에는 S-protein이 77~138%, S-carbohydrate가 77~212%까지 증가하였다. 또한 투과 전자현미경을 통해 전자빔 조사 전후의 적조세포 관측을 통하여 세포의 파괴 및 세포내 구성물질의 용출을 확인할 수 있었다. 이렇듯 적조에 전자빔을 조사함으로써 Extracellular Biopolymer에 의한 Flocculation을 유도하여 적조를 침강 제어할 수 있다. 또한 전자빔 조사 전 후 Alexandrium catenella의 PSP(Paralytic Shellfish Poisoning) 패독 분석 결과 1 kGy의 전자빔을 조사함으로써 전자빔을 조사하지 않은 적조 대비 PSP 독성 함량이 48% 감소하여 전자빔조사가 유독적조의 사멸 뿐만 아니라 제독에도 효과가 있음을 알 수 있었다.

• Korean Chemical Engineering Research
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• 제46권5호
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• pp.1002-1007
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• 2008

이 논문의 목적은 PEMFC 작동을 위한 플라즈마 개질 시스템의 최적 조건을 연구한 것이다. 플라즈마 개질 반응기는 니켈 촉매 반응기와 동시에 사용하여 수소 생성을 증대하였다. 또한 수성가스 전환 반응기 및 선택적 산화 반응기는 연료전지의 촉매 피독에 영향을 주는 일산화탄소의 농도를 10 ppm 이하로 줄이기 위하여 제작되었다. 플라즈마 개질기에서 최대 수소생산 조건은 S/C 비 3.2, 메탄 2.0 L/min, 촉매반응기 온도는 $700{\pm}5^{\circ}C$ 그리고 입력전력 900 W이다. 이때의 합성가스의 농도는 $H_2$ 70.2%, CO 7.5%, $CO_2$ 16.2%, $CH_4$ 1.8% 이다. 수소 수율, 수소 선택도 그리고 메탄 전환율는 각각 56.8%, 38.1%, 92.2%이다. 에너지 효율과 에너지 요구량은 37.0%, 183.6 kJ/mol 이다. 추가적으로 $CO_2/CH_4$ 비 실험을 진행하였다. 또한 수성가스 전환 반응기는 플라즈마 개질 반응기의 최적조건으로 실험을 진행하였으며, 출구 농도는 $H_2$ 68.0%, CO 337 ppm, $CO_2$ 24.0%, $CH_4$ 2.2%, $C_2H_4$ 0.4%, $C_2H_6$ 4.1% 이다. 이때의 선택적 산화 반응기의 실험결과는 $H_2$ 51.9%, CO 0%, $CO_2$ 17.3%를 나타냈다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.184-187
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• 2007

Hydrogen could be produced from any substance containing hydrogen atoms, such as water, hydrocarbon (HC) fuels, acids or bases. Hydrocarbon fuels couold be converted to hydrogen-rich gas through reforming process for hydrogen production. Even though fuel cell have high efficiency with pure hydrogen from gas tank, it is more beneficial to generate hydrogen from city gas (mainly methane) in residential application such as domestic or office environments. Thus hydrogen is generated by reforming process using hydrocarbon. Unfortunately, the reforming process for hydrogen production is accompanied with unavoidable impurities. Impurities such as CO, $CO_2$, $H_2S$, $NH_3$, and $CH_4$ in hydrogen could cause negative effects on fuel cell performance. Those effects are kinetic losses due to poisoning of electrode catalysts, ohmic losses due to proton conductivity reduction including membrane and catalyst ionomer layers, and mass transport losses due to degrading catalyst layer structure and hydrophobic property. Hydrogen produced from reformer eventually contains around 73% of $H_2$, 20% or less of $CO_2$, 5.8% of less of $N_2$, or 2% less of $CH_4$, and 10ppm or less of CO. Most impurities are removed using pressure swing adsorption (PSA) process to get high purity hydrogen. However, high purity hydrogen production requires high operation cost of reforming process. The effect of carbon dioxide on fuel cell performance was investigated in this experiment. The performance of PEM fuel cell was investigated using current vs. potential experiment, long run (10 hr) test, and electrochemical impedance measurement when the concentrations of carbon dioxide were 10%, 20% and 30%. Also, the concentration of impurity supplied to the fuel cell was verified by gas chromatography (GC).

• 한국식품위생안전성학회지
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• 제15권2호
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• pp.176-178
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• 2000

V. parahaemolyticus를 균주로 alkaline protease 생산을 위한 질소원의 종류, skim milk농도, NaCl농도, 금속이온의 종류를 조사하였다. 질소원인 peptone, tryptone, casamino acid, ski milk, phyton peptone중에서는 skim milk에서 활성이 월등히 높게 나타났고, skim milk의 농도에 따른 실험에서는 2%일 때 활성이 가장 높게 나타났다. NaCl의 농도에 따른 실험에서는 0%일 때 활성이 가장 높았고 농도가 높아질수록 활성이 낮아졌다. 금속이온에 따른 활성을 보면 금속이온이 들어가지 않았을 때 활성이 가장 높게 나타났고, 금속이온을 첨가하므로써 활성이 급격히 떨어졌다. 또한 CoCl$_2$, CuCl$_2$, HgCl가 첨가되었을 때는 활성이 전혀 나타나지 않았다.

• Animal Bioscience
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• 제34권4호
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• pp.734-742
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• 2021

Objective: The present study aimed to investigate the occurrence and species of coagulase-positive staphylococci (CoPS) and coagulase-negative staphylococci (CoNS) in retail pork meat samples collected during nationwide monitoring. The staphylococcal isolates were characterized for antimicrobial and zinc chloride resistance and enterotoxigenic potential. Methods: A total of 260 pre-packaged pork meat samples were collected from 35 retail markets in 8 provinces in Korea for isolation of staphylococci. Antimicrobial and zinc chloride resistance phenotypes, and genes associated with the resistance phenotypes were determined on the isolates. Furthermore, the presence and distribution of 19 staphylococcal enterotoxin (SE) genes and enterotoxin-like genes among the pork-associated staphylococci were determined by multiplex polymerase chain reaction-based assays using the specific primer sets. Results: A total of 29 staphylococcal strains (29/260, 11.1%) were isolated from samples of retail pork meat, 24 (83%) of which were CoNS. The four CoNS species identified were S. saprophyticus (n = 16, 55%), S. sciuri (n = 3, 10%), S. warneri (n = 3, 10%), and S. epidermidis (n = 2, 7%). Among the 29 isolates, four methicillin-resistant CoNS (MR-CoNS; three S. sciuri and one S. epidermidis) and one methicillin-resistant CoPS (MR-CoPS; one S. aureus) were identified. In addition, a relatively high level of tetracycline (TET) resistance (52%) was confirmed in CoNS, along with a predominant distribution of tet(K). The most prevalent SEs were sep (45%), and sen (28%), which were carried by 81% of S. saprophyticus. Conclusion: These findings suggest that CoNS, especially S. saprophyticus strains, in raw pork meat could be a potential risk factor for staphylococcal food poisoning (SFP), and therefore, requires further investigation to elucidate the role of SEls in SFP and virulence of the pathogen. Our results also suggest that CoNS from raw pork meat may act as a source for transmission of antimicrobial resistance genes such as staphylococcal cassette chromosome mec and tet(K).