• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.889-890
• /
• 2006

In recent years, PCB drills with smaller diameters less than 0.1 mm are used and thus there are growing needs for ultra-fine grained cemented carbides. However, ultra-fine WC powder usually causes extraordinary grain growth during sintering which weakens mechanical strength of ultra-fine grained cemented carbides. So we examined several kinds of WC powders to make new ultra-fine grained cemented carbides having superior performance. We found that direct carburized WC powder is very good as a WC raw material. The PCB drills made of the developed ultra-fine grained cemented carbides have higher hardness, toughness and stiffness than conventional ones.

• 한국표면공학회지
• /
• 제29권5호
• /
• pp.512-518
• /
• 1996

Amorphous carbon nitride (a-C:N) multilayerfilms are formed by using altermating conditions during film deposition in are ion plating process. Because hard a-C:N films prepared with suitable megative bias voltages have large compressive stress, it is difficult to increase film thickness more than 200nm. Preparing multilayer films composed of hard layers and soft layers, we can grow thick multilayer films on Si and SKH steel substrate. The total thickness of multilayer films is more than 1$\mu\textrm{m}$. The multilayer films are several times thicker than the single layer films and almost equal in hardness and internal stress to the single layer ones. X-ray photoelectron spectroscopy(XPS) and Raman spectroscopy reveal that multilayer films equal to single layer films in structure, which is similar to the structure of DLC films.

• 한국표면공학회지
• /
• 제29권5호
• /
• pp.363-370
• /
• 1996

Carbon nitride is one of the new carbon materials which show interesting properties. After the theoretical calculation by LIu and Cohen, many researchers are trying to prepare $\beta$-$C_3N_4$ which may be harder than diamond. Many carbon nitride films synthesized till now by various methods are amorphous and the N/C ratios in the films are usually below 0.5. First we review shortly the synthesis of carbon nitride thin films by plasma, ion and laser processing. Second we report on the preparation of amorphous carbon nitride thin films by shielded arc ion plating and the structural and mechanical properties of the films.

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
• /
• pp.63-64
• /
• 2012

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
• /
• pp.61-62
• /
• 2012

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2009년도 심포지엄 및 춘계학술발표회
• /
• pp.379-380
• /
• 2009

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.849-854
• /
• 2008

We have been developing a 1500N-thrust Swirling-Oxidizer-Flow-Type hybrid rocket engine. In order to put the engine into practical use, we conducted long duration burning experiments up to 25s to examine the influence of configuration change of fuel grain on the engine performance and designed an LOX vaporization nozzle to supply GOX for the 1500N-thrust engine. The experiment with a small hybrid rocket engine showed that combustion was stable and the engine performance was approximately constant during combustion. There was no essential problem to with increasing combustion time. The LOX vaporization nozzle designed had 30 rectangular channels with a depth of 0.5mm. During passing through the nozzle, the LOX increased in temperature and vaporized sufficiently.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2008년도 Asian Magnetics Conference
• /
• pp.4.2-4.2
• /
• 2008

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.222.2-222.2
• /
• 2003

The Araliae continental is Radix is the root of Aralia continentalis Kitagawa, which belongs to the Araliaceae and is distributed in Korea, Japan, Manchuria, China and Sahalane. It is generally used as a folk medicine for its excellent medical action and efficacy in various symptoms such as headache, edema, inflammation, rheumatism and neuralgia. (-)-Pimara-8(14)-15-dien-19-oic acid (1) and l-kaur-16-en-19-oic acid have been reported as the major constituent of A. continental is Radix. Essential oils such as limonene, sabinene, myrcene, humulene and sesamin, ${\beta}$-sitosterol are also reported as constituent elements. (omitted)

• Anatomy and Cell Biology
• /
• 제57권1호
• /
• pp.7-12
• /
• 2024

The pterygomandibular raphe (PMR) is a tendinous structure connecting the bucinator and the superior pharyngeal constrictor muscles. With its implications in the spread of oral cancer, the proper treatment of obstructive sleep apnea, and dental procedures, it is important to obtain a thorough understanding of the PMR. We reviewed the existing literature to compile the published information regarding its anatomy, embryology, imaging, variations, functions, pathologies, and clinical relevance of the pterygomandibular raphe.