• Journal of Electrical Engineering and Technology
• /
• 제6권2호
• /
• pp.233-238
• /
• 2011

In the present work, a new approach is proposed for via interconnects of semiconductor devices, where multi-wall carbon nanotubes (MWCNTs) are used instead of conventional metals. In order to implement a selective growth of carbon nanotubes (CNTs) for via interconnect, the buried catalyst method is selected which is the most compatible with semiconductor processes. The cobalt catalyst for CNT growth is pre-deposited before via hole patterning, and to achieve the via etch stop on the thin catalyst layer (ca. 3nm), a novel 2-step etch scheme is designed; the first step is a conventional oxide etch while the second step chemically etches the silicon nitride layer to lower the damage of the catalyst layer. The results show that the 2-step etch scheme is a feasible candidate for the realization of CNT interconnects in conventional semiconductor devices.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.169-171
• /
• 2007

A breaking layer was introduced to conventional decal transfer method in membrane electrolyte assembly fabrication for high catalyst transfer ratio. In this study, the modified decal transfer method with high catalyst transfer ratio was introduced and its performance is studied. The structural features of electrodes made by decal method were investigated using scanning electron microscopy and current-voltage polarization measurement.

• 한국염색가공학회지
• /
• 제9권4호
• /
• pp.1-6
• /
• 1997

Water repellent finish was carried out using water repellent agent(AG-480), melamine resin(Sumitex Resin MK), and catalyst(Sumitex Accelerator ACX). PET/nylon fabrics were treated with melamine resin by pad-dry-cure method and subsequently washed and dried. Durable water repellency was controlled by the melamine resin and catalyst. Water repellency was tested by spray rating method and durability of water repellency were measured by launder-O-meter and pilling tester. The optimum conditions of durable water repellent finish for new synthetic fabric were as follows; concentration of water repellent finishing agent 20g/l; concentration of melamine & catalyst 0.5g/l; curing condition $160^{\circ}$ ${\times}$ 30sec. Water repellency after washing and rubbing is improved by melamine resin and catalyst.

• Bulletin of the Korean Chemical Society
• /
• 제29권2호
• /
• pp.389-392
• /
• 2008

High purity carbon nano fibers/tubes (CNF/Ts) which contain 97% pure graphitic carbon are prepared by a new catalytic method. These carbon nano fibers/tubes are ready to use without any further purification. The striking feature of this method is the production of carbon nano fibers/tubes of narrow distribution range. The developed catalytic method also produces pure hydrogen. An additional advantage of this catalytic method is that catalyst can be reused without reactivation. Ni:Cu catalyst system is embodied into SCHOTT-DURAN filter disc of large pore size (40-100 mm). Due to the production of hydrogen in the reaction catalyst stability is enhanced and deactivation process is considerably slowed down.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 춘계학술대회
• /
• pp.55-58
• /
• 2006

An experimental study is performed to evaluate the performance and the efficiency by humidifying MEA and by making the double-layered catalyst in a fuel cell system which is taken into account the physical and thermal concept. An electrical output produced by PEMFC(Polymer Exchange Membrane Fuel Cell) is measured to assess the performance of the stack and the efficiency is also evaluated according to the different situation in which is placed with and without the humidification of MEA(Membrane Electrolyte Assembly). Subsequently, It is found that the measured values of MEA voltage and current are influenced by the MEA temperature, humidification, and the double-layered catalyst which gives more enhanced values to apply for electric units.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 춘계학술대회
• /
• pp.107-109
• /
• 2006

This study focuses on a determination of amount of Pt in the Pt/C for catalysts of polymer electrolyte membrane fuel cells (PEMFC). PEMFC offer low weight and high power density and being considered for automotive and stationary power applications. The PEMFC performance is influenced by several factors, including catalysts and structure of electrode and membrane type. Catalyst of electrode is important factor for PEMFC. One of the obstacles prevent ing polymer electrolyte membrane fuel cells from commercialization is the high cost of noble metals to be used as catalyst, such as platinum To effectively use these metals, they have to be will dispersed to small particles on conductive carbon supports. The optimal amount of Pt in Pt/C for cathode catalyst was investigated by using polarization curves in single cell with $H_2/O_2$ operation.

• Bulletin of the Korean Chemical Society
• /
• 제20권1호
• /
• pp.89-94
• /
• 1999

Carbon dioxide reforming of methane on Ni/γ-Al2O3 catalyst was studied. A new 10 wt% Ni/γ-Al2O3 catalyst prepared by the liquid phase oxidation method (L10O) exhibited much higher activity as well as resistances to both sintering and coke formation during the reaction than the catalyst prepared by the conventional impregnation method (D10). The electrically strong attractive interaction between nickel and support during the liquid phase oxidation process and the resultant high nickel dispersion made the L10 have superior activity and stability to the D10. To elucidate the results, the experiments with nickel catalysts on the other supports as well as 7-AI203 were performed. The effect of sodium as a promoter was also studied.

• World Technopolis Review
• /
• 제8권1호
• /
• pp.43-58
• /
• 2019

This paper examine the changing ecosystems in Malaysia, starting with the government policy driven greenfield cluster of Cyberjaya, which is part of the Multimedia Super Corridor (MSC) mega project. In this context of an emerging economy, predominantly production oriented, the role of the government was crucial with respect to implementing policies and building infrastructure for the ecosystems. First, the roles played by the cluster development agency, universities, and industry are explained. As the cluster developed, this paper, taking an entrepreneurial ecosystem approach, explores how some actors evolved and changed their roles to become catalyst organisations established for the cluster now serving nationwide. This was followed by the emergence of new actors in the ecosystems, for example, knowledge intermediaries, and new roles for universities. In addition to actors such as universities and industry, this paper recognizes the emergence of media organisations as new actors in the entrepreneurial ecosystems in Malaysia.

• 한국수소및신에너지학회논문집
• /
• 제17권3호
• /
• pp.293-300
• /
• 2006

KIER has been developing a Ru-based preferential oxidation catalysts and a novel fuel processing system to provide hydrogen rich gas to residential PEMFCs system. The catalytic activity of Ru-based catalysts was investigated at different Ru loading amount and different support structure. The obtained result indicated that 2 wt% loaded Ru-based catalyst supported on ${\alpha}-Al_2O_3$ showed high activity in low temperature range and suppressed the methanation reaction. The developed prototype fuel processor showed thermal efficiency of 78% as a HHV basis with methane conversion of 92%. CO concentration below 10 ppm in the produced gas is achieved with separate preferential oxidation unit under the condition of $[O_2]/[CO]=2.0$. The partial load operation have been carried out to test the performance of fuel processor from 40% to 80% load, showing stable methane conversion and CO concentration below 10 ppm. The durability test for the daily start-stop and 8 h operation procedure is under investigation and shows no deterioration of its performance after 50 start-stop cycles. In addition to the system design and development.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.86.2-86.2
• /
• 2010

In order to improve polymer electrolyte membrane fuel cell (PEMFC) durability, the durability of membrane electrode assemblies (MEA), in which the electrochemical reactions actually occur, is one of the vital issues. Many articles have dealt with catalyst layer degradation of the durability-related factors on MEAs in relation to loss of catalyst surface area caused by agglomeration, dissolution, migration, formation of metal complexes and oxides, and/or instability of the carbon support. Degradation of catalyst layer during long-term operation includes cracking or delamination of the layer which result either from change in the catalyst microstructure or loss of electronic or ionic contact with the active surface, can result in apparent activity loss in the catalyst layer. Membrane degradation of the durability-related factors on MEAs can be caused by mechanical or thermal stress resulting in formation of pinholes and tears and/or by chemical attack of hydrogen peroxide radicals formed during the electrochemical reactions. All of these effects, the mechanical damage of membrane and degradation of catalyst layers are more facilitated by uneven stress or improper MEA fabrication process. In order to improve the PEMFC durability, therefore, it is most important to minimize the uneven stress or improper MEA fabrication process in the course of the fabrication of MEA. We analyzed the effects of the MEA fabrication condition on the PEMFC durability with MEA produced using CCM (catalyst coated membrane) method. This paper also investigated the effects of MEA fabrication condition on the PEMFC durability by adding additional treatment process, hot pressing and pressing, on the MEA produced using CCM method.