• 한국보건간호학회:학술대회논문집
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• 2006.06b
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• pp.179-180
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• 2006

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3429-3434
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• 2007

An experimental study was carried out to investigate gasification process of wood sawdust in the I-dimensional downdraft fixed bed gasifier. The preheated air was used oxidizer and steam were used as a gasifying agent. The operating parameters, the supplied air temperature and steam were used. The oxidizer temperature was varied from 500K to 620K and vapor was added. The gasification process was monitored by measuring temperature at three position near the biomass using R-type thermocouples and the syngas composition was analyzed by gas chromatograph. The change of hydrogen and carbon monoxide, carbon dioxide, methane was observed. Overall, the volume fraction of hydrogen and methane were increased widely as increasing the oxidizer temperature and adding steam.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3423-3428
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• 2007

This paper shows that inlet humidity condition at cathode side is one of dominant parameters affecting the performance of PEMFC. To investigate effects of inlet humidity condition, the performance measurements were conducted for a single PEMFC with two operating variables : cathode relative humidity and dry condition in anode dry. The fuel cell employed for the experiments is a unit PEMFC with a 25$Cm^2$, Nafion$^(R)$112 membrane. As a result of this study, the cell performance is getting higher by increasing inlet humidity condition at cathode side. The cell performance is different from each operating temperature an it has maximum30% higher than dry condition at 60$^{\circ}C$ operating temperature with 80% relative humidity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.12 s.255
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• pp.1228-1235
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• 2006

PEMFC(Proton Exchange Membrane Fuel Cell) is a low temperature fuel cell and has many probabilities of commercial use. However, water management is one of the serious technical problems for commercialization. It is necessary to understand the relationship between operation conditions and water behavior in PEMFC channel because it affects fuel cell performance. In this paper, the distribution of current density according to inlet humidity condition is mainly observed and discussed. If the anode inlet is well humidified, electro-osmotic drag is very active. For this reason, current density is very high at inlet side and the distribution is non-uniform.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.31 no.2
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• pp.87-91
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• 2020

The tracheostomy directs external air into the airway tract. This process causes mucosal dryness, irritation and inflammation in the tracheo-bronchial tree. In order to prevent such problems, several methods are applied; ointment application, humidification and careful suction etc. The heat-moisture exchanger (HME) is commercially sold device that assists heating and humidification of the inhaled air. The authors experienced successful treatment outcome of intractable tracheitis caused by repetitive and vigorous intra-tracheal suction by applying HME in a total laryngectomized patient. We report an interesting and didactic case with a brief literature review.

• 한국전기화학회:학술대회논문집
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• 2001.06a
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• pp.133-138
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• 2001

• Air Cleaning Technology
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• v.28 no.4
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• pp.24-36
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• 2015

• Journal of the Korean Electrochemical Society
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• v.8 no.4
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• pp.149-154
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• 2005

Fuel cell performance evaluation logic was developed using G-language (LabVIEW) to measure performance stability. Degree of stability and reliability of performance data were improved with averaged value and standard deviation method. Water injection system was introduced and the performance using this method was comparable to that of conventional humidification method. Water injection system has advantage of lowering operation energy consumption, reducing the number of parts needed in humidification, therefore increasing efficiency of fuel cell system. Fuel cell performance was decreased in case of low temperature operation such as sub freezing condition. Air purge method was tested to reduce the water content in cell fixture before sub freezing condition. The performance degradation due to low temperature operation was minimized by air purge method in medium size cell fixture ($25cm^2$) case.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.1-4
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• 2002

The occurrence rate of russet in 'Whangkeumbae' pear showed significant difference by years because the russet occurrence is greatly affected by the amount of rainfall. This study was conducted to analyse the relationship between rainfall and russet occurrence by artificial treatment of high humidity. Under high relative humidity condition, stomatal resistance decreased and average fruit weight was higher since the increased net photosynthesis rate accumulation accelerated fruit growth. The russet occurrence began on July 25, when the growth speed of fruit weight and fruit surface is the most fast. Russet occurrence rate was higher in high relative humidity condition because the fruit growth was accelerated. Since the fruit calcium concentration change is extreme in late July, it is assumed that the deceased calcium content is related to the occurrence of russet in 'Whangkeumbae' pear, When the high relative humidity condition is maintained after rainfall, the amount of net photosynthesis rate increase and fruit growth is accelerated. Therefore, the unbalance in the amounts of transferred photosynthesis assimilation product, water and mineral elements would be one of the reasons for the russet occurrence in 'Whangkeumbae' pear.

• Clean Technology
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• v.13 no.2
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• pp.99-103
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• 2007

Pt/Nafion self-humidifying membranes for Polymer Electrolyte Membrane Fuel Cell (PEMFC) were synthesized via a supercritical-impregnation method. The Nafion 112 membranes were impregnated with Pt(II) acetylacetonate from a supercritical carbon dioxide ($scCO_2$) solution at $80^{\circ}C$ and 19.8 MPa. After the impregnation, the Pt-impregnated Nafion membrane was converted Pt deposited Nafion(Pt/Nafion) membrane by reducing agent, sodium borohydride ($NaBH_4$) under $50^{\circ}C$ and 2 hours. The prepared Pt/Nafion membranes were investigated by SEM, EDS and EPMA. The performance of the Pt/Nafion membranes was examined in PEMFC as a self-humidifying membrane. The cell performance of the Pt/Nafion membrane at $65^{\circ}C$ is better than that of Nafion 112.