• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.411.1-411.1
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• 2016

In this study, we examined the effects of boron doping on the dielectric reliability of solution processed aluminum oxide ($Al_2O_3$). When boron is doped in aluminum oxide, the hysteresis reliability is improved from 0.5 to 0.4 V in comparison with the undoped aluminum oxide. And the accumulation capacitance is increased when boron was doped, which implying the reduction of the thickness of dielectric film. The improved dielectric reliability of boron-doped aluminum oxide is originated from the small ionic radius of boron ion and the stronger bonding strength between boron and oxygen ions than that of between aluminum and oxygen ions. Strong boron-oxygen ion bonding in aluminum oxide results dielectric film denser and thinner. The leakage current of aluminum oxide also reduced when boron was doped in aluminum oxide.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.600-605
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• 1998

Present study was investigate to evaluate the aluminum absorption effect on lactic acid bacteria(Lactobacillus acidophilus ATTC 4356, Lactogacillus bulgaricus ATTC 11842, Lactobacillus casei IFO 3533, and Streptococcus thermophilus KCTC 2185 ; LAB) and Clostridium perfringens ATCC 3627 (CP) in artificial intestinal tract. Their growth rate, aluminum accumulation and cellular distribution was studied under anaerobic broth system. All of above microbes were inhibited by adding 10 to 100ppm of aluminum. The degree of aluminum in LAB (Lactobacillus acidophilus ATCC 4356, Lactobacillus bulgaricus ATCC 11842, Lactobacillus casei IFO 3533, and Streptococcus thermophilus KCTC 2185) was higher than of CP. The largest amount of aluminum was accumulated in Lactobacillus bulgaricus ATCC 11842. Aluminum accumulation in LAB was distributed in 49.1% at cell wall, 27.3% at plasma membrane, and 23.6% at cytoplasm, respectively. This study suggests that LAB might help to eliminate the ingested aluminum in intestinal tract.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.632-637
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• 2003

In this study, the effect of surface treatment of CFRP and aluminum on the fracture toughness of CFRP/aluminum composites was investigated. CFRP was surface-treated by Ar$^{+}$ ion beam under oxygen environment, and the aluminum was surface-treated by DC plasma. CFRP was adhesively bonded to aluminum using the secondary bonding procedure. Cracked lap shear specimens were used to determine fracture toughness. Three cases of cracked lap shear specimens were made depending on the surface treatment. The values of fracture toughness of three cases were compared to each other It was found that the fracture toughness of ion beam-treated CFRP/aluminum composites was almost 72 % higher than that of unrented CFRP/aluminum composites. The fracture toughness of CFRP/plasma-treated aluminum composites was 50 % higher than that of untreated CFRP/aluminum composites.s.

• Corrosion Science and Technology
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• v.7 no.3
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• pp.158-161
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• 2008

It is well known that iron is one of the most common impurity elements found in aluminum and its alloys. Iron in the aluminum forms an intermetallic compounds such as $FeAl_3$. The $FeAl_3$ particles on the aluminum surface are one of the most detrimental phases to the corrosion process and anodizing procedure for aluminum and its alloys. Trial and error surface treatment will be carried out to find the preferential and effective removal of $FeAl_3$ particles on the surfaces without dissolution of aluminum matrix around the particles. One of the preferable surface treatments for the aim of getting $FeAl_3$ free surface was an electrochemical treatment such as cathodic current density of $-2kAm^{-2}$ in a 20-30 mass% $HNO_3$ solution for the period of 300s. The corrosion characteristics of aluminum surface with $FeAl_3$ free particles are examined in a $0.1kmol/m^3$ NaCl solution. It is found that aluminum with free $FeAl_3$ particles shows higher corrosion resistance than aluminum with $FeAl_3$ particles.

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.322-329
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• 2020

The utilization of aluminum scrap is a subject of great importance in terms of reducing energy consumption and environmental protection. However, aluminum scrap contains impurities, which can degrade the properties of aluminum alloy, especially corrosion resistance. This study examines the effect of scrap charge rate of aluminum alloys about microstructures and corrosion characteristics. According to the metallographic examinations, Mg2Si tended to become coarser and its uniformity was decreased by increasing aluminum scrap charge rate. The immersion test exhibited corrosion progressed through the eutectic areas due to micro-galvanic interactions. Electrochemical measurements revealed that excess aluminum scrap could reduce the intergranular corrosion resistance of aluminum alloys. Results showed that the scrap charge rate is important factor in the design of corrosion resistance of aluminum die casting alloys.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.72-78
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• 2024

The lightweight and high strength characteristics of aluminum alloy materials make them have promising prospects in the field of construction engineering. This paper primarily focuses on aluminum alloy materials. Aluminum alloy was combined with concrete, wood and carbon fiber reinforced plastic (CFRP) cloth to create a composite column. The axial compression test was then conducted to understand the mechanical properties of different composite structures. It was found that the pure aluminum tube exhibited poor performance in the axial compression test, with an ultimate load of only 302.56 kN. However, the performance of the various composite columns showed varying degrees of improvement. With the increase of the load, the displacement and strain of each specimen rapidly increased, and after reaching the ultimate load, both load and strain gradually decreased. In comparison, the aluminum alloy-concrete composite column performed better than the aluminum alloy-wood composite column, while the aluminum alloy-wood-CFRP cloth composite column demonstrated superior performance. These results highlight excellent performance potential for aluminum alloy-wood-CFRP composite columns in practical applications.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.1
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• pp.87-97
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• 1997

The purpose of this study was to evaluate the method for quantitative assessment of bone mass from aluminum-equivalent value of hydroxyapatite by using digital imaging system consisted of Power Macintosh 7200/120, 15-inch color monitor, and GT-9000 scanner with transparency unit. After aluminum-equivalent image made from correlation between aluminum thickness and grey scale, the accuracy of conversion to mass from aluminum-equivalent value was evaluated. Measured bone mass was compared with converted bone mass from aluminum-equivalent value of hydroxyapatite block by correlation formula between aluminum-equivalent value of hydroxyapatite block and hydroxyapatite mass. The results of this study were as follow; 1. Correlation between aluminum thickness and grey level for obtaining aluminum-equivalent image was high positively associated(r²=0.99). Converted masses from aluminum-equivalent value were very similar to measured masses. There was, statistically, no significant difference(P<0.05) between them 2. Correlation between hydroxyapatite aluminum-equivalent and hydroxyapatite mass was shown to linear relation (r²=0.95). 3. Converted masses from aluminum-equivalent value of 3 dry mandible segments were similar to measured masses. The difference between the exposure directions was not significantly different(P<0.05).

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.331-336
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• 2004

The correlation between polymeric aluminum species of coagulant and its coagulation efficiency was investigated using several commercial polymeric Al(III) inorganic coagulants (Poly Aluminum Hydroxy Chloro Sulfate 2020 (PAHCS2020), Poly Aluminum Hydroxy Chloro Sulfate 2500 (PAHCS2500) which was introduced in Korean water treatment plants. The poly aluminum chloride (PAC), Poly Aluminum Hydroxide Chloride Silicate (PACS)) and the aluminum salts ($AlCl_3$, Alum ($Al_2(SO_4)_3$)) were used for the purpose of comparison. The comparison of the coagulation efficiency of each coagulant was made by turbidity removal through the standard jar testing procedure and the determination of the hydrolytic Al(III) species was made by the ferron method which can differentiate the monomeric aluminum species from the polymeric aluminum species. Overall, PAHCS2020 and PAHCS2500 showed the better performance in turbidity removal than the aluminum salts. The performance of coagulation was even better without adjustment of pH during the coagulation experiment. The positive correlation between polymeric aluminum species of coagulant and coagulation efficiency was found.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.501-506
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• 2005

With the respective collapse characteristics of aluminum and CFRP (Carbon Fiber Reinforced Plastics) tubes in mind, axial collapse tests were performed for aluminum/CFRP compound tubes, which are composed of square or circular shaped aluminum tubes wrapped with CFRP outside. In this study, the collapse modes and the energy absorption characteristics were analyzed for aluminum/CFRP compound tubes which have different fiber orientation angle of CFRP. Fracture modes in the aluminum/CFRP compound tubes were rather stable than those in the CFRP tubes alone, probably due to the ductile nature of the inner aluminum tubes. The absorbed energy per unit volume of the aluminum or the aluminum/CFRP compound tubes was higher than that of CFRP tubes. Meanwhile, the absorbed energy per unit mass, for the light-weight design aspect was higher in the aluminum/CFRP compound tubes than in the aluminum tubes or the CFRP tubes. The energy absorption turned out to be higher in circular tubes than in square tubes. Beside the collapse modes and the energy absorption characteristics were influenced by the orientation angle, and the compound tubes took the most effective energy absorption when the fiber orientation angle of CFRP was 90 degrees.

• Journal of the Korean Ceramic Society
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• v.32 no.6
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• pp.677-684
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• 1995

The effect of catalytic graphitization of petroleum cokes by the addition of aluminum were investigated. The degree of graphitization carbon body only fired at 230$0^{\circ}C$ was 0.5. But when the aluminum additive was added, the degree of graphitization was increased to 0.93. And Ts-effect was appeared as the catalytic effect. This effect was occurred by the formation-decomposition of aluminum carbide through the reaction of aluminum and cokes.