• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.432-436
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• 2007

We have studied on the tribological characteristics of Plasma Vapour Deposition(PVD) coating method in Automotive Structural Materials. Coating materials were deposited by the Titanium carbide(TiC) and Titanium nitride(TiN). An experimental process was established to determine the tribological characteristics of friction and wear behaviour with the variation of applied load, temperature and the time with the Falex friction and wear test machine. It was improved that when the surface modification of hard coatings(TiC, TiN) was deposited steel, the tribological characteristics become better. It is argued that it is improved because of excellence of the anti-wear, the extreme pressure properties and tile heat stability.

• Journal of the Korean institute of surface engineering
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• v.40 no.2
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• pp.70-76
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• 2007

Ni-P-SiC composite coating layers were prepared by electroless plating method and their deposition rate, codeposition of SiC, morphology, surface roughness, hardness, wear and friction properties were investigated. The deposition rate was kept almost constant independent of the concentration of SiC in the plating solution and the codeposition of SiC in the composite coating layer increased with increased concentration of SiC in the plating solution except the early stage. Vickers microhardness increased with respect to the increased codeposition of SiC and the heat treatment at $300^{\circ}C$ in air for 1 hour. It was found that the wear volume decreased with increased up to 50 wt.% of SiC codeposition, and that friction coefficient increased gradually with increased codeposition of SiC. Considering the wear and the friction behaviors, the composite coating layer obtained by using 50 wt.% of SiC codeposition is desirable for the practical application for anti-wear and anti-friction coatings.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3083-3093
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• 1993

Friction and wear at ceramic coated surfaces of aluminum alloy were experimentally studied using a Ring-on-Block wear test machine. Ceramic materials coated on aluminum alloy surfaces were WC, CrC, $Al_{2}O_{3}$ by a plasma spray; and $Al_{2}O_{3}$,$Al_{2}SiO_{5}$, $Na_{2}B_{4}O_{7}$,$Na_{4}P_{2}O_{7}$, and $Al_{2}O_{3}-ZrO_{2}$ composite coating by an Anodic Spark Depositon. They were tested under the sliding wet contact and compared with aluminum alloys and steels. Test results showed that ceramic coated surfaces, in general, have better anti-wear property than those of aluminum alloys due to increase in the surface hardness ; however, they also showed higher coefficients of friction and changes in wear mechanisms, resulting in brittle fractures.

• KSTLE International Journal
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• v.10 no.1_2
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• pp.33-36
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• 2009

The nuclear steam generator is composed of a bundle of tubes. The length of these tubes is very long, but their diameter is small. Fluid exists inside of the steam generator and its flow causes vibration, therefore these tubes are supported by anti-vibration bars. The wear damage due to the vibration is known as fretting wear, which should be minimized to ensure the safety of the plants. Research needs to be done about decreasing the amount of fretting wear. Hard coatings have proven to be very effective in reducing the amount of wear. The commercial coatings of TiN and CrN have excellent wear resistance and are used to protect the Inconel tube from fretting wear. The tube-on-flat type tester was used for conducting the fretting wear tests. It was found that the wear amounts of the coated tubes decreased depending on the coating thickness. CrN was found to be very effective in reducing the wear, while the wear amounts were dependent on the coating thickness in the case of TiN and a thick coating of TiN was very effective on wear resistance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1739-1744
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• 2010

In this study, the bioactivities of ethanol (EEAR) and water extract (WEAR) from the leaf of Aceriphyllum rossii were investigated. In the anti-oxidative activity, IC50 of DPPH radical scavenging activity was respectively 549.86 and $62.14{\mu}g$/mL by EEAR and WEAR. Anti-inflammatory activity of EEAR and WEAR has been evaluated on inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) release by the macrophage RAW 264.7 cells. EEAR and WEAR inhibited inflammatory by 5.58 and 16.85% in 10 mg/mL, respectively. In the anti-diabetic activity, $IC_{50}$ of $\alpha$-glucosidase inhibitory activity was 5.62 and $425.63{\mu}g$/mL by EEAR and WEAR. $IC_{50}$ of $\alpha$-amylase inhibitory activity of EEAR and WEAR was 4,623.87 and over $10,000{\mu}g$/mL, respectively. In the anti-obesity, all lipase inhibitory activity ($IC_{50}$) of EEAR and WEAR was up $10,000{\mu}g$/mL. Finally, EEAR and WEAR exhibited anti-oxidative and anti-diabetic activity. It suggests that Aceriphyllum rossii could be potentially used as a resource of bioactive materials for health functional foods.

• Journal of the Korean Society of Costume
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• v.41
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• pp.153-168
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• 1998

The purpose of this study is to examine, specifically, the external and internal characteristics of anti-fashion expression in the Korean student movement after the 1945 Liberation. The dress expressed in the student movement represented the purity of student and characterized resistance, and this character expressed strongly in 80s, faded from middle of 90s. Until the 60s, the student movement was not characterized by, so activist students wore dress and suits. It symbolized students as an elite group of society. They added on head-bands to express resistance. In the 70s, activist students wore school uniforms, school military training wear, blue jeans and loose shirts in demonstrations. They tried to express re-bellion against the government and the older gen-eration. In the 80s, the period was remarkably distingusihing by the economic growth at that time. Activist students wore T-shirts with Korean letters and popular paintings specially made, Korean costumes, wrapped in the Taggeuki (Korean national flag), and refused wear on jeans because of anti-Americanism. They also wore masks, muffled their faces, and got their heads shaved. These anti-fashions are very strong expressions for the national independence spirit, national traditional heitage, anti-foreign power and anti-American. In the early 90s, activist students wore reformed Korean costumes specially made group uniforms, after that they wore casual everyday clothes with caps. They tried to express remarkable resistance in the early 90s, but after the mid-90s expression of resistance weakened and faded, so there was no distinction between activist and non-activist. There are the reasons why the student movement changed after the peaceful transfer of political power.

• Tribology and Lubricants
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• v.11 no.1
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• pp.50-57
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• 1995

When engine oil is used under severe running condition, the Lubricational characteristics is very important. I have studied the Lubricational characteristics with Compound Additives of engine oil for the Falex wear test machine. Adding detergent (Ca-phenate) to engine oil, the seizure is more improved than in case of non-adding, and adding Zn-DTP (Zinc dialkyl dithio phosphate), the extreme pressure property is excellent at the high load. But when the PTFE (Polytetra Fluoro Ethylene) and MoS$_{2}$ (Molybdenum disulfide) are added, the temperature characteristics and the anti-wear property become excellent because the stability can be maintained in a high temperature. The result are as follows, it can be improved that when the compound of the Ca-phenate and Zn-DTP, MoS$_{2}$, PTFE, etc. was added to engine oil, the lubrication characteristics become better. It is argued that it is improved because of excellence of the anti-wear, the extreame pressure properties and the heat stability.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.2
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• pp.1-7
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• 2005

In order to determine the wear Properties of PECVD ceramic coatings, wear process was evaluated using the coated pin of Falex Tribosystem. Coating materials deposited wear the TiC, TiN and Ti(CN). An experimental process was established to determine the tribological characteristics of friction and wear behavior under the variation of applied load, temperature and sliding distance by the Falex test machine. The experimental results indicate that TiN coating compared with TiC coating on e materials have e excellent friction and wear characteristics. However TiC coating compared i친 TiN coatings have a low friction coefficient with steel and good thermal stability, and Ti(CN) has the excellent anti-wear properly as well as the superiority of extreme pressure property. Compound coating compared wi simple coatings show improved tribological characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1245-1252
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• 1999

The sliding wear behavior of $Al_2O_3/NiCr$ coating deposited on steel(SM45C) was investigated under lubrication. The parameters of sliding wear are normal loads, coating thickness. As a result, the wear resistance of $Al_2O_3/NiCr$ coating was remarkably greater than that of $Al_2O_3$ coating. The optimized coating thickness was found to be $300{\mu}m$ to ensure good anti-wear. The bond coating played important role in decreasing residual stress. The residual stress had much influence on wear mechanism. These results were correlated with the stress state of coating and the microstructure of coating.

• Journal of the Korean Ceramic Society
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• v.31 no.8
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• pp.874-878
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• 1994

To increase the anti-oxidation and anti-wear properties of graphite for the propellant-burning environment, SiC, Pt and Al2O3 multi-layer coatings were conducted succesisvely and the optimum condition was researched. The SiC layer was produced by pack cementation and SiC layer in thickness of 30 ${\mu}{\textrm}{m}$ coating was produced after coating for 6 hours. Pt layer was coated by sputtering, and the Al2O3 layer was coated by reactive sputtering. the thickness of Pt layer and Al2O3 layer was less than one-tenth of that of SiC layer. The pack coated specimens and multi-layer coated specimens were made using above conditions and test-fired. The test result showed that the wear rate of SiC layer is approximately 1/10 compared to that of uncoated graphite.