• Journal of the Korean Society of Industry Convergence
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• v.12 no.3
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• pp.143-147
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• 2009

The enantioselective reduction of representative prochiral alkyl-aryl ketones with a new chiral alkoxy-amine-aluminum derivatives from aluminum hydride and ${\alpha},{\alpha}$-diphenyl-${\beta}$-amino alcohols, such as (S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol(AMDPB) and (S)-(-)-2-(diphenylhydroxy-methyl)pyrrolidine(DPHMP), in THF at $0^{\circ}C$ was studied. In the reduction of alkoxy-amine-aluminum derivatives, acetophenone, propiophenone, isopropiophenone, and butyrophenone are reduced to corresponding aromatic secoundary alcohols with 34~60 % enantiomeric excess of (S)-isomers. For such ketones, the optical induction was enhanced by increasing a size of alkyl groups.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.34-37
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• 2005

While all-aluminum front end carriers have been frequently used by major foreign auto-makers, the carriers domestically produced are typically hybrid types. It is understood that higher fuel efficiency due to weight reduction can be achieved by using aluminum carriers because of aluminum's light weight. Moreover, aluminum is expected to posess high corrosion resistance and recyling rate. As a first step to enhance feasibility of domestic production of all-aluminum carriers, several carriers made by advanced auto makers are examined and compared. Besides basic characteristics such as appearance and weight, physical properties including composition, strength and elongation are carefully analyzed to obtain critical design and process factors.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.291-294
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• 2005

Recently, the usage of aluminum alloy is rapidly increasing in automobile industry to achieve weight reduction for fuel efficiency. However, design of forming process of aluminum is more difficult than steel because of poor formability and severe springback. Since applications of finite element analysis for the design of sheet metal forming process are actively performed, it is required to conduct proper consideration of aluminum material behavior. In this study, a plane stress yield function Yld2000(Yoon et al., 2000), proven to describe well the anisotropic behavior of aluminum alloy, is implemented for FE analysis. One element test is considered to verify the validity of implementation of Yld2000 model. In addition, cylindrical cup drawing test is performed to verify earing shape of a drawn cup.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.219-220
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• 2000

We propose a new method for the formation of an aluminum parting layer in the fabrication of field emitter arrays, in which we used a reflow property of aluminum at a lower temperature than the deformation point of glass. After the sputtered aluminum layer on the gate metal was etched for the formation of gate holes, we carried out a rapid thermal annealing process, by which the aluminum slightly diffused into the gate hole. This reflowed aluminum could be used as a parting layer and emitter arrays were easily fabricated using this method.

• Journal of the Korean Chemical Society
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• v.58 no.1
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• pp.85-91
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• 2014

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

• Corrosion Science and Technology
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• v.3 no.4
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• pp.161-165
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• 2004

Aluminum source in an Al-Fe coating reacts with molten carbonate and develops a protective $LiAlO_2$ layer on the coating surface during operation of molten carbonate fuel cells (MCFC). However, if aluminum content in an Al-Fe coating decreases to a critical level for some reasons during MCFC operation, a stable and continuous $LiAlO_2$ protective layer can no longer be maintained. The aluminum content in an Al-Fe coating can be depleted by two different processes; one is by corrosion reaction at the surface between the aluminum source in the coating and molten carbonate, and the other is inward-diffusion of aluminum atoms within the coating into a substrate. In these two respects, therefore, the decreasing rate of aluminum concentration in an Al-Fe coating was measured, and then the influences of these two aspects on the lifetime of Al-Fe coating were investigated, respectively.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.164-167
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• 2009

The applications of the aluminum alloy sheets to the auto-body panels are dramatically increasing for weight reduction of the automobiles. However, low formability of the aluminum alloy sheet compare to the steel sheet can be obstacles in tool manufacturing process. Therefore, much of yield criteria for the anisotropic material such as the aluminum alloy sheet have been observed. In this study, the biaxial tensile test and FLD test for the aluminum alloy sheet are performed. The results are compared with Hill's 1948 and Hill's 1990 model by means of theoretical predictions. Finite element analysis also performed using the proposed method for the real panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.127-130
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• 2007

A new front plate structure of ac-PDP was explored using fence-type aluminum electrode coated with anodic aluminum oxide.[1] In this structure, ITO and glass dielectric layer were eliminated and expensive Ag BUS electrode was replaced with aluminum. Test panels were prepared using the new structure and their luminance and discharge characteristics were examined. These results indicate that the new structure provide a new way of cost reduction and enhancement of performance of ac-PDPs

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.84-87
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• 2000

Square tubes used for vehicle structure components have an important role on keeping its stiffness and preserving occupant safety in vehicle collision and rollover in which it experience axial collapse, bending collapse or both. Bending collapse, which absorbs kinetic energy of the impact and retains a survival space for the occupant, is a dominant failure mode in oblique collision and rollover. Thus, in this paper, the bending collapse characteristics such as the maximum bending moment and energy absorption capacity of the square tube replaced by light-weight material were evaluated and presented. The bending test of cantilever tubes which were fabricated with aluminum, GFRP and aluminum/ GFRP hybrid by co-curing process was performed. Then the maximum bending moment and the energy absorption capacity from the moment-angle curve were evaluated. Based on the test results, it was found that aluminum/ GFRP hybrid tube can show better specific energy absorption capacity compared to the pure aluminum or GFRP tube and can convert unstable collapse mode which may occur in pure GFRP tube to stable collapse mode like a aluminum tube in which plastic hinge is developed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.138-142
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• 2016

In this study, a strength analysis was performed to assess die-cast aluminum alloy brake pedals as an improved alternative to wrought alloys. Aluminum brake pedal shapes are considered to be suitable for the die-casting process. The strength criterion of Volvo trucks was used as the criterion for the pedal strength. The results of this analysis showed that the frame thickness of the aluminum brake pedal must be increased from 12 mm to 18 mm to have a strength superior to that of a steel brake pedal. Additionally, the stress and weight of the aluminum brake pedal were found to be approximately 24% and 26% lower than those of the steel brake pedal, respectively. Mounting tests and strength assessments verified that the proposed die-cast aluminum alloy brake pedal demonstrated sufficient strength.