• Proceedings of the KSME Conference
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• 2000.11a
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• pp.363-369
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• 2000

Due to environmental problem for reduction in fuel consumption, vehicle emission and etc., many automotive makers are trying to reduce the weight of the vehicle. The most effective way to reduce the weight of vehicle is to use lighter materials, aluminum, plastics. Aluminum Space Frame has many advantages in weight reduction, body stiffness, ease of model change and so on. So, most of automotive manufacturers are attempting to develope Aluminum Space Frame body. For these reasons, we have developed Aluminum Intensive Vehicle based on steel monocoque body with Hyundai Motor Company. We achieved about 30% weight reduction, the stiffness of our model was higher than that of conventional steel monocoque body. In this paper, with optimization using FEM analysis, we could get more weight reduction and body stiffness increase. In the long run, we analyzed by means of simulation using PAM-CRASH to evaluate crush and crash characteristic of Aluminum Intensive Vehicle in comparison to steel monocoque automotive.

• Journal of the Korean Electrochemical Society
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• v.5 no.4
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• pp.226-231
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• 2002

Power densities produced by the permeation of methanol through membranes were directly measured by inserting the membrane in front of anode in a membrane-electrode-assembly of a direct methanol fuel cell (DMFC). The power density was closely related to the loss of power in the DMFC and was strongly affected by temperature. As the cell temperature was increased, the power density resulting from methanol crossover was increased. The increase in methanol crossover had be attributed to diffusion caused or affected by temperature. Methanol crossover a major effect on the performance of a DMFC at a relatively low temperature with $26\%\;loss\;at\;30^{\circ}C$. In order to reduce methanol crossover, a conventional Nafion membrane was modified by the incorporation of Pt or Pd. The reduction in methanol crossover was investigated in these modified membranes by our cell performance measurement. Pt and Pd particles incorporated in the Nafion membranes block methanol pathway and prevent methanol transport through the membranes, which was proved by combining with liquid chromatography.

• Journal of Welding and Joining
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• v.26 no.4
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• pp.50-54
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• 2008

In this research, anode for SOFC has been manufactured from two different kinds of feedstock materials through thermal spraying process and the properties of the coatings were characterized and compared. One kind of feedstock was manufactured from spray drying method which includes nano-components of NiO, YSZ (300 nm) and graphite. And the other is manufactured by blending the micron size NiO coated graphite, YSZ and graphite powders as feedstock materials. Microstructure, mechanical properties and electrical conductivity of the coatings as-sprayed, after oxidation and after hydrogen reduction containing nano composite which is prepared from spray-dried powders were evaluated and compared with the same properties of the coatings prepared from blended powder feedstock. The coatings prepared from the spray dried powders has better properties as they provide larger triple phase boundaries for hydrogen oxidation reaction and is expected to have lower polarization loss for SOFC anode applications than that of the coatings prepared from blended feedstock. A maximum electrical conductivity of 651 S/cm at $800^{\circ}C$ was achieved for the coatings from spray dried powders which much more than that of the average value.

• Journal of Welding and Joining
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• v.34 no.5
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• pp.19-25
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• 2016

Global warming is hot issue to keep the earth everlastingly. Despite the increase of the world population and the energy demand, the world oil supply and the oil price are hold the steady state. If we are not decrease the world population and the energy consumption, unforeseeable energy crisis will come in the immediate future. AMT acronym of Advanced Materials for Transportation is a non-profitable IEA-affiliated organization to mitigate the oil consumption and the environment contamination for the transportation. In recent, Annex X Multi-materials Joining was added to enhance the car body weight reduction cause the high fuel efficiency and the low emission of exhaust gas. Multi-materials are the advanced materials application technology to optimize the weight, the performance and the cost with the combination of different materials such as Al-alloy, Mg- alloy, AHSS and CFRP. In this study, the trends of AMT strategy and Al-alloy based multi-materials joining technology were review. Also several technologies for Al-alloy dissimilar joining were investigated.

• Corrosion Science and Technology
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• v.6 no.5
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• pp.245-250
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• 2007

Recently, to avoid global warming, reduction of $CO_2$ generation has been demanded. Each car manufacture takes positive actions for improvement in fuel consumption by various kinds of countermeasures, e.g. improving engine efficiency, using alternative fuels, lightening the car body. Regarding lightening of the car body, aluminum alloys and high tensile strength steels has been gradually adopted as lightweight materials. However, such materials are normally not easy to be treated with zinc phosphate system. Focusing the pre-treatment processes, low temperature phosphate system could be demanded for energy saving. This time, new surface conditioning process for lightweight materials and low temperature phosphate system shall be discussed.

• Elastomers and Composites
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• v.46 no.1
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• pp.10-21
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• 2011

Recently, with developments in the automotive industry, sound and vibration damping have a considerable attraction with a diversified customer needs and advanced automobile. In general, among various materials, textile materials, such as felt and glass fibers, polyurethane foam, and PET fiber materials were used to reduce sound and vibration of the automobile. These materials were located in various main parts of the automobile to block sound and vibration, resulting in a comfortable ride. In addition, to improve fuel economy, weight reduction and cost saving for the automobile were also being considered together as well as the reduction of sound and vibration of the automobile. Therefore, in this paper, we focused on the need of interior sound and vibration absorption materials in the automobile and absorption materials-related technologies.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.4
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• pp.351-358
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• 2015

In the recent times, the use of gasoline direct injection (GDI) engines has been regarded as a means of enhancing conformance to emission regulations and improving fuel efficiency. GDI engines have been widely adopted in the recent years for their better engine performance and fuel economy compared to those of conventional MPI gasoline engines. However, they present some disadvantages related to the mass and quantity of particulate matter generated during their use. This study investigated the nanoparticle characteristics of the particulate matter exhausted from a GDI engine vehicle installed with different types of gasoline particulate filters, after subjecting it to ultra-lean burn driving conditions. Three metal foam and metal fiber filters were used for each experimental condition. The number concentrations of particles were analyzed for understanding their behavior, and the reduction characteristics were obtained for each type of filter.

• Clean Technology
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• v.24 no.3
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• pp.212-220
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• 2018

Oxy-fuel combustion is considered as a promising greenhouse gas reduction technology in power plant. In this study, the behaviors of NO and $SO_2$ were investigated under the condition that in-furnace $deNO_x$ and $deSO_x$ methods are applied in oxy-fuel circulating fluidized bed combustion condition. In addition, the generation trends of $SO_3$, $NH_3$ and $N_2O$ were observed. For the purpose, limestone and urea solution were directly injected into the circulating fluidized bed combustor. The in-furnace $deSO_x$ method using limestone could reduce the $SO_2$ concentration in exhaust gas from ~403 to ~41 ppm. At the same experimental condition, the $SO_3$ concentration in exhaust gas was also reduced from ~3.9 to ~1.4 ppm. This trend is mainly due to the reduction of $SO_2$. The $SO_2$ is the main source of the formation of $SO_3$. The negative effect of $CaCO_3$ in limestone, however, was also appeared that it promotes the NO generation. The NO concentration in exhaust gas reduced to ~26 - 34 ppm by appling selective non-catalytic reduction method using urea solution. The $NH_3$ concentration in exhaust gas was appeared up to ~1.8 ppm during injection of urea solution. At the same time, the $N_2O$ generation also increased with increase of urea solution injection. It seems that the HNCO generated from pyrolysis of urea converted into $N_2O$ in combustion atmosphere. From the results in this study, the generation of other pollutants should be checked as the in-furnace $deNO_x$ and $deSO_x$ methods are applied.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.188-191
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• 2007

This paper shows the Development of In-tank pressure regulator and Solenoid Valve used in FCV(Fuel Cell Vehicle). We have developed new type of Regulator and Solenoid through analysis of the structure and characteristics of component of FCS(Fuel Cell System) from the advanced technology. Now it is possible to localize the component by making use of the development of Regulator and Solenoid made by us. Regulator and Solenoid is a equipment to control hydrogen pressure supplied into a stack. Therefore, outlet pressure, a flow of fluid and temperature are important parameters according to a inlet pressure. And leak test, endurance test and burst test should be done to guarantee the performance and safety of Regulator and Solenoid used in the fuel of high pressure. Also, Hydrogen friendly materials are applied to inner parts of the Regulator, Solenoid and weight reduction is done to cost saving in part not related to performance. As a result, we have proven the good performance and reliability in endurance of Regulator, Solenoid and will make an development in performance as well as durability to ensure industrialization.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.237-240
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• 2002

Micro catalytic reactors are alternative propulsion device that can be used on a nano satellite. When used with a monopropellant, $H_2O_2$, a micro catalytic reactor needs only one supply system as the monopropellant reacts spontaneously on contact with catalyst and releases heat without external ignition, while separate supply lines for fuel and oxidizer are needed for a bipropellant rocket engine. Additionally, $H_2O_2$ is in liquid phase at room temperature, eliminating the burden of storage for gaseous fuel and carburetion of liquid fuel. In order to design a micro catalytic reactor, an appropriate catalyst material must be selected. Considering the safety concern in handling the monopropellants and reaction performance of catalyst, we selected hydrogen peroxide at volume concentration of 70% and perovskite redox catalyst of lantanium cobaltate doped with strondium. Perovskite catalysts are known to have superior reactivity in reduction-oxidation chemical processes. In particular, lantanium cobaltate has better performance in chemical reactions involving oxygen atom exchange than other perovskite materials. In the present study, a process to prepare perovskite type catalyst, $La_{0.8}Sr_{0.2}CoO_3$, and measurement of its propellant decomposition performance in a test reactor are described.