• Title/Summary/Keyword: Carbon-monoxide

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Effect of Temperature and Reactants Flow Rate on the Synthesis Gas Production in a Fixed Bed Reactor (고정층 반응기에서 합성가스 생성에 미치는 반응온도와 반응물 유속의 영향)

  • Kim, Sang-Bum;Kim, Young-Kook;Hwang, Jae-Young;Kim, Myung-Soo;Hahm, Hyun-Sik
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.1
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    • pp.45-50
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    • 2004
  • The effects of reaction temperature and flow rate of reactants on the methane conversion, product selectivity, product ratio, and carbon deposition were investigated with 13wt% Ni/MgO catalyst. Reaction temperatures were changed from 600 to $850^{\circ}C$, and reactants flow rates were changed from 100 to 200 mL/mim. There were no significant changes in the methane conversion observed in the range of temperatures used. It is possibly stemmed from the nearly total exhaustion of oxygen introduced. The selectiveties of hydrogen and carbon monoxide did not largely depend on the reaction temperature. The selectivities of hydrogen and carbon monoxide were 96 and 90%, respectively. Carbon deposition observed was the smallest at $750^{\circ}C$ and the largest at $850^{\circ}C$. It is found that the proper reaction temperature is $750^{\circ}C$. The best reactant flow rate was 150 ml/min.

A Study on the Steam-Hydrocarbon Reforming Catalysts (탄화수소의 수증기개질 촉매에 관한 연구)

  • Lee Mook Kwon;Tae Soon Kim
    • Journal of the Korean Chemical Society
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    • v.15 no.2
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    • pp.55-63
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    • 1971
  • In this study, several nickel catalysts for the steam-hydrocarbon reforming process were prepared from various nickel salt, magnesium oxide, alumina and kaolinite. The activity and strength of the catalysts were investigated. 1. The proper composition of the calcined catalysts are: NiO (5-15%)-MgO(10-20%)-$Al_2O_3$(10-40%)-Kaolinite(50-80%). 2. The admixed or cosedimented ingredients of the catalysts was pelletized and calcinated at 1000 or $1150^{\circ}C$. Calcination at $1150^{\circ}C$ for an hour was optimum. 3. The water to oil ratio (W/O) for reforming of hexane should be above 7 mole/mole. As the W/O increases, more carbon dioxide and hydrogen, but less carbon monoxide was produced. Also carbon deposition become lessen at higher W/O. 4. Maximum conversion had attained at about $850^{\circ}C$. As the reaction temperature increases, more carbon monoxide and hydrogen, but less carbon dioxide and lower hydrocarbon was produced. 5. The percent conversion at $850^{\circ}C$ was about 80%, using a catalyst which the nickel oxide content are 5%.

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PaCO2 at Early Stage is Associated with Adverse Cardiovascular Events in Acute Carbon Monoxide Poisoning (급성 일산화탄소 중독 환자에서 응급실 내원 초기 동맥혈 이산화탄소 분압의 임상적 의미)

  • Yang, Keun Mo;Chun, Byeong Jo;Moon, Jeong Mi;Cho, Young Soo
    • Journal of The Korean Society of Clinical Toxicology
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    • v.17 no.2
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    • pp.86-93
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    • 2019
  • Purpose: The objective was to determine the association between PaCO2 and adverse cardiovascular events (ACVEs) in carbon monoxide (CO)-poisoned patients. Methods: This retrospective study included 194 self-breathing patients after CO poisoning with an indication for hyperbaric oxygen therapy and available arterial blood gas analysis at presentation and 6 hours later. The baseline characteristics and clinical course during hospitalization were collected and compared. The mean PaCO2 during the first 6 hours after presentation was calculated. Results: The incidence rates of moderate (30 mmHg< PaCO2 <35 mmHg) or severe (PaCO2 ≤30 mmHg) hypocapnia at presentation after acute CO poisoning were 40.7% and 26.8%, respectively. The mean PaCO2 during the first 6 hours was 33 (31-36.7) mmHg. The incidence of ACVEs during hospitalization was 50.5%. A significant linear trend in the incidence of ACVEs was observed across the total ranges of PaCO2 variables. In multivariate regression analysis, mean PaCO2 was independently associated with ACVEs (OR 0.798 (95% CI 0.641-0.997)). Conclusion: Mean PaCO2 during the first 6 hours was associated with increased ACVEs. Given the high incidence of ACVEs and PaCO2 derangement and the observed association between PaCO2 and ACVEs, this study suggests that 1) PaCO2 should be monitored at the acute stage to predict and/or prevent ACVEs; and 2) further study is needed to validate this result and investigate early manipulation of PaCO2 as treatment.

Carbon monoxide activation of delayed rectifier potassium currents of human cardiac fibroblasts through diverse pathways

  • Bae, Hyemi;Kim, Taeho;Lim, Inja
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.1
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    • pp.25-36
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    • 2022
  • To identify the effect and mechanism of carbon monoxide (CO) on delayed rectifier K+ currents (IK) of human cardiac fibroblasts (HCFs), we used the wholecell mode patch-clamp technique. Application of CO delivered by carbon monoxidereleasing molecule-3 (CORM3) increased the amplitude of outward K+ currents, and diphenyl phosphine oxide-1 (a specific IK blocker) inhibited the currents. CORM3-induced augmentation was blocked by pretreatment with nitric oxide synthase blockers (L-NG-monomethyl arginine citrate and L-NG-nitro arginine methyl ester). Pretreatment with KT5823 (a protein kinas G blocker), 1H-[1,-2,-4] oxadiazolo-[4,-3-a] quinoxalin-1-on (ODQ, a soluble guanylate cyclase blocker), KT5720 (a protein kinase A blocker), and SQ22536 (an adenylate cyclase blocker) blocked the CORM3 stimulating effect on IK. In addition, pretreatment with SB239063 (a p38 mitogen-activated protein kinase [MAPK] blocker) and PD98059 (a p44/42 MAPK blocker) also blocked the CORM3's effect on the currents. When testing the involvement of S-nitrosylation, pretreatment of N-ethylmaleimide (a thiol-alkylating reagent) blocked CO-induced IK activation and DL-dithiothreitol (a reducing agent) reversed this effect. Pretreatment with 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)-21H,23H porphyrin manganese (III) pentachloride and manganese (III) tetrakis (4-benzoic acid) porphyrin chloride (superoxide dismutase mimetics), diphenyleneiodonium chloride (an NADPH oxidase blocker), or allopurinol (a xanthine oxidase blocker) also inhibited CO-induced IK activation. These results suggest that CO enhances IK in HCFs through the nitric oxide, phosphorylation by protein kinase G, protein kinase A, and MAPK, S-nitrosylation and reduction/oxidation (redox) signaling pathways.

The prediction of emission concentrations in spark ignition engine with EGR system (EGR장치를 부착한 전기점화기관에서의 배출물농도 여측)

  • 김용일;김응서
    • Journal of the korean Society of Automotive Engineers
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    • v.6 no.3
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    • pp.36-44
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    • 1984
  • The prediction of the emission concentrations in 4-cycle 4-cylinder spark ignition engine is made by considering the model with the extended Zedovich mechanism. The predicted values for nitric oxide, carbon dioxide and carbon monoxide agree with the experimentally measured ones.

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