• Journal of the Korean Electrochemical Society
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• v.10 no.2
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• pp.110-115
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• 2007

Solid oxide fuel cell(SOFC) has high fuel flexibility due to its high operating temperatures. Hydrocarbonaceous fuels such as diesel has several advantages such as high energy density and established infrastructure for fuel cell applications. However diesel reforming has technical problems like coke formation in a reactor, which results in catastrophic failure of whole system. Performance degradation of diesel autothermal reforming (ATR) leads to increase of undesirable hydrocarbons at reformed gases and subsequently degrades SOFC performance. In this study, we investigate the degradation of SOFC performance(OCV, open circuit voltage) under hydrocarbon(n-Butane) feeds and characteristics of diesel performing under various ratios of reactants($H_2O/C,\;O_2/C$ molar ratios) for improvement of SOFC performance. Especially we achieved relatively high performance of diesel ATR under $H_2O/C=0.8,\;O_2/C=3$ condition.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.341-347
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• 2010

In this study, the efficiency of a solid-oxide fuel cell (SOFC) system with a steam reformer or prereformer was analyzed under various conditions. The main components of the system are the reformer, SOFC, and water boiling heat recovery system. Endothermic and exothermic reactions occur in the reformer and SOFC, respectively. Hence, the thermal management of the SOFC system greatly influences the SOFC system efficiency. First, the efficiencies of SOFC systems with a steam reformer and a prereformer are compared. The system with the prereformer was more efficient than the one with steam reformer due to less heat loss. Second, the system efficiencies under various prereformer operating conditions were analyzed. The system efficiency was a function of the heat requirement of the system. The efficiency increased with an increase in the operating temperature of the prereformer, and the maximum system efficiency was observed at $450^{\circ}C$ for a S/C of 2.0.

• Journal of the Korean Electrochemical Society
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• v.19 no.4
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• pp.134-140
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• 2016

An aptamer-based biosensor using a new redox indicator has been examined for the electrochemical detection of thrombin. The aptamer modified primary aliphatic amine was covalently immobilized onto poly-(5,2':5',2"-terthiophene-3'-carboxylic acid) (polyTTCA) layer. Tetrabromophenolphthalein ethyl ester (KTBPE) was interacted to aptamer and used as an electrochemical indicator. Prior to the detection, the oxidation reaction of KTBPE onto aptamer modified layer was also investigated using differential pulse voltammetry. The characterization of the final sensor (KTBPE/aptamer -polyTTCA) was performed by voltammetry, QCM, and ESCA. After binding of thrombin onto KTBPE/aptamer based sensor, the peak signal of KTBPE was gradually decreased. The sensor exhibited a dynamic range between 10.0 and 100.0 nM with the detection limit of $1.0{\pm}0.2nM$.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.576-583
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• 2023

This study aimed to investigate the impact of enhancing the electrode conductivity and mitigating the production of hydrogen peroxide - a by-product arising from lactate oxidation - on the performance of lactate electrodes. The electrical conductivity of the electrode was improved by modifying the surface of carbon paper with single-walled carbon nanotubes. Catalase was introduced to effectively eliminate the hydrogen peroxide produced during the lactate oxidation reaction. The carbon paper electrode, with simultaneous immobilization of both lactate oxidase and catalase, yielded a current 1.7 times greater than the electrode where only lactate oxidase was immobilized. The electrode in which lactate oxidase and catalase were co-immobilized on the surface of carbon paper modified with single-walled carbon nanotubes, produced a current of 171 µA, which was more than twice as much current as the carbon paper with only lactate oxidase immobilized. The optimized electrode showed a linear response up to lactate concentration of 20 mM, confirming that it can be used as a sensor electrode.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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• pp.206-211
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• 2017

Carbon felt electrode for the vanadium redox-flow battery (VRFB) has been studied to see the effect of grephene oxide (GO) treatment on the surface of the carbon felt electrode. In this paper, surface of carbon felt electrodes were treated with various concentrations of grephene oxide. Electrochemical analysis, cyclic voltammetry (CV), was performed to investigate redox characteristics as electrode for VRFB. Also the effect of GO on the introduction of functional group on the surface of carbon felt electrodes were investigated using X-ray photoelectron spectroscopy (XPS), which discovered increase in the overall functional group content on the surface of carbon felts.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.97-98
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• 2012

This research examined the fundamental property of the MgO as the fundamental study that substituted the MgO in the low melting point modified sulfur mortar to examine the physical properties.In this research, the table floor, flexural strength test, and compressive strength test were performed. And as the replacement ratio increased, the floor showed the tendency to increase. And when being the replacement ratio 3%, the flexural strength and compressive strength made the high strength. In case of being substituted for over 5% they displayed the tendency that the intensity is degraded.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.114-115
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• 2014

Recently, the construction structure repeats the brilliant development including the shper high rising, high functionalization, environmental friendliness, conversion to ubiquitous, and etc. upon with the construction industry development and it is continually soothed. Meanwhile, as to the construction structure of the modern society, the research for corresponding to the box-frame construction way where the response to the diversity of the life of the occupant is difficult is needed. Thus, the lightweight of the structure is the important factor in order to secure the functionality. Therefore, this research tries to study the water absorption ratio and flexural strenght of the magnesium oxide light weight matrix according to the powdery modified sulfur addition ratio.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.59-62
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• 2008

The performance behavior of solid oxide fuel cell using reformate gas as fuels was investigated. When the pre-reformate gas was used without steam, the maximum power density was 50% lower than that using H2. This may be due to carbon deposition caused by the pyrolysis of remaining hydrocarbons. However, when the steam was added, the maximum power density showed a relatively small variation according to reformate gas. When pre-reformate gas with steam was fed into anode, the SOFC showed the stable performance without sharp voltage drop during 10h operation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.127-128
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• 2014

현재 기술 산업에서 PET위 무전해 도금을 실행하기 위해 다양한 전처리 공정과 Catalyst가 소개되고 있다. 그 중에서 가장 일반적으로 사용되고 있는 Catalyst는 Palladium으로서 Tin과 산화 환원 반응으로 Electroless Copper Deposition 단계에서 구리 도금의 Target으로 작용하고 있다. 하지만 상대적으로 Palladium은 생산 비용이 높으며 Tin은 쉽게 산화되는 문제점이 남아 있다. 이를 대체하기 위한 대안 공정으로서 Palladium 대신 Silver를 이용하여 Catalyst로서의 역할을 하는 공정이다. 이전에 PET위 전처리 공정으로 Ultra Violet을 사용하여 표면을 개질 시키는 방법을 연구했으며, 그 후 Potassium Permanganate와 Silver Catalyst의 Mechanism을 연구 했다. PET 표면 개질을 거치면서 화학 구조가 바뀌어 표면에 Carbon Carbon Double Bond를 형성한다. 이때 Permanganate ion이 새로이 형성된 이중 결합과 반응하여 두 개의 extra-OH functional group을 생성함과 동시에 $MnO_2$를 만들어 표면에 흡착 시킨다. $MnO_2$는 전위차에 의해 Silver Ion과 Redox Reaction을 일으키며 실질적인 Catalyst 역할을 하게 된다. Silver Catalyst는 무전해 구리 도금 용액 안에서 Copper의 Target으로 작용한다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.156-157
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• 2015

Recently, the trend for structure is being changed from wall construction to rhamen construction. rhgamen construction reduces floor noise and selfweight in structures. The amount of lightweight panels used in rhamen construction is also increasing. Also, Worldwide refinery industry is a large amount of sulfur is produced by develrop ment. Sulfur is resistant to freezing and thawing. Terefore, this study focuses on the density and absorption of magnesium oxide matrix that contains wood powder and pearlite to replace lightweight panel for rhamen construction. Adding pearlite 15% has the lowest density but, it has the highest absorption.