• Journal of the Mineralogical Society of Korea
• /
• v.11 no.2
• /
• pp.97-105
• /
• 1998

Weathering of biotite in Palgonsan granite was studied by using X-ray diffraction, optical microscopy, scanning electron microscopy, and electron probe micro analysis. Biotite altered to biotite/vermiculite regular mixed layer mineral (B/V) in the early stage of weathering. Although partially replaced by kaolinite with the progress of weathering. B/V is the major weathering product of biotite throughout the profile. During the formation of B/V, Mg, Fe and K are removed from a biotite layer to form a vermiculite layer by about 28%, 44% and 88%, respectively, whereas the Ti content is not changed. Considerable volume increase after the kaolinitization of B/V suggests that Al and Si are largely introduced from the external weathering solution. The silicate lattice templet of a weathering biotite facilitated the nucleation and growth of kaolinite. In the Palgongsan granite weathering profile, plagioclase weathered mostly into halloysite whereas biotite greatly contributes to the kaolinite crystallization though its small content in fresh rock.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.839-840
• /
• 2006

Sintering behavior of the Fe-0.8Mn-0.5C powder system was studied on the specimens with a density of ${\sim}7.0g/cc$ sintered at $1120^{\circ}C$ for 30 min in a gas mixture of $7%H_2/93%N_2$ with the inlet dew point of $-60^{\circ}C$. During the atmosphere monitoring ($CO/CO_2$-content and dew point) was showed, that carbothermical reduction occurs in two different temperature ranges; three peaks of dew point profile also can be distinguished during sintering cycle as well. Following sintering the Mn-content distribution and microstructures around the Mn-source were micro-analytical evaluated; the results showed that manganese travels through porous iron matrix up to ${\sim}60{\mu}m$.

• Journal of the East Asian Society of Dietary Life
• /
• v.12 no.3
• /
• pp.218-224
• /
• 2002

This study was undertaken to analyze chemical composition, macro- and micro-mineral contents of ostrich bone with flesh meat (BF), ostrich bone with flesh meat with herb medicine (BFll) and ostrich bone with internal organs (BI). Crude fat of the BFH was lower, but crude protein and crude ash of the BFH were significantly higher than those of the BF and the BI. Among the minerals, Ca, p, Mg, Fe, Cu, Zn content of the BFH were significantly higher than the content in the BF and the BI. The minerals, Pb, Cd and As were not detected in ostrich and herb medicine extracts. From the sensory test of ostrich and herb medicine, the preferences were in the fellowing order; ostrich bone with flesh meat with herb medicine (BFH), ostrich bone with flesh meat (BF), and ostrich bone with internal organs (BI) in extracts.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10b
• /
• pp.1067-1070
• /
• 2000

WAP(Wireless Application Protocol)을 기반으로 한 무선 인터넷 분야의 발전과 더불어 엄청나게 늘어난 무선 인터넷 이용자들의 컨텐츠에 대한 요구가 다양해지고 있다. 따라서 CP(Content Provider)들은 무선 장비에 맞게 설계된 WML(Wireless Markup Language)과 WMLScipt를 무선 장비를 사용하지 않고, 실제와 비슷한 상황에서 컨텐츠(Content)를 개발할 수 있는 환경이 필요하게 되었다. 본 논문에서는 무선 웹 컨텐츠를 좀 더 쉽게 개발할 수 있도록 도와주는 WML 마이크로 브라우저의 구현에 대해 기술한다. WML 마이크로 브라우저는 WML 파싱(parsing) 모듈과 브라우징(Browsing)모들로 구성되고. 클라이언트 측 WAP 스택으로 요청한 결과로 얻은 컨텐츠를 화면에 출력한다.

• Corrosion Science and Technology
• /
• v.3 no.5
• /
• pp.222-225
• /
• 2004

A portable RF HTS SQUID-based susceptometer was applied to the measurement of fatigue behavior for type 316L(N) stainless steel containing 0.04% to 0.15% nitrogen content. Strain-controlled low cycle fatigue (LCF) tests were conducted at RT and $600^{\circ}C$ in air an atmosphere, and the magnetic moments were measured after the fatigue test using HTS SQUID. The magnetic moment of an as-received sample is higher than that of a fatigued sample in all the temperature ranges irrespective of the nitrogen content. The fatigue life decreased with an increasing test temperature up to $500^{\circ}C$, but increased at $600^{\circ}C$. The change of the magnetic moments by LCF test is attributed to the stress induced micro defects.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.473-476
• /
• 2006

In this study, evaluation of fire-resistant performance for polypropylene fiber-mixed mortar was performed to establish specification for stability of tunnel structure against fire afterward. In the fire-resistant performance test with mix proportion of polypropylene fiber, cracks were observed for mortar under 0.15% of fiber content, but micro-cracks were remarkably reduced for mortar more than 0.2% of fiber content. From the results, we are concluded that optimal mix proportion of polypropylene fiber is $0.20{\sim}0.25%$.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.477-480
• /
• 2006

In this study, evaluation of fire-resistant performance for polypropylene fiber-mixed mortar was performed to establish specification for stability of tunnel structure against fire afterward. In the fire-resistant performance test with mix proportion of polypropylene fiber, cracks were observed for mortar under 0.15% of fiber content, but micro-cracks were remarkably reduced for mortar more than 0.2% of fiber content. From the results, we are concluded that optimal mix proportion of polypropylene fiber is $0.20{\sim}0.25%$.

• Journal of Pharmaceutical Investigation
• /
• v.18 no.4
• /
• pp.169-174
• /
• 1988

The release of heparin from monolithic devices composed of different ratios of polyethylene oxide-polypropylene oxide (PEO-PPO) and hydrophobic polyurethane was investigated. The release rate of heparin could be controlled by varying the PEO-PPO content. The heparin release rate from the devices increased as the content of PEO-PPO in the devices increased. The release mechanism may be associated with creation of micro-channels and pores through the devices following the change in the physical structure of the polymer network. Hydrophobic polyurethane containing PEO-PPO can provide an antithrombogenic material for prolonged release of heparin from a heparin blended system.

• Journal of the Korean institute of surface engineering
• /
• v.30 no.2
• /
• pp.144-154
• /
• 1997

Effects of plasma nitriding on the surface charcteristice of stainless steel(SS) were investjgated by utilizing wear tester, micro-hardness tester and potentiostat. The surface and corrosion morphology of plasma nitrided SS were analyzed by utilizing optical microscopy, SEM, XRD and WDX. It was found that plasma nitriding at $550^{\circ}C$, compared with $380^{\circ}C$, prodiced a good wear resistance and hardness as nitriding time increased, whereas Mo addition showd that were resistance and hardness decreased. Intergranular corrosion(IGC) resistance improved significantly in the case of plasma nirtrided SS containing 4.05wt% Mo at $380^{\circ}C$ because that nitrogen and Mo ast syner gidically to form a protective layer on surface which is responsible for the aggresive SCN-ion. Plasma nitrided at $550^{\circ}C$ decreased IGC as Mo content increased. Pitting improved in the plasma nitirided SS at Mo content incresased owing to retard a nucleation and growth of chromium carbide or nitirde in grain boundary.

• Journal of Aquaculture
• /
• v.7 no.2
• /
• pp.109-122
• /
• 1994

The cultured olive flounder larvae given nutrient enriched rotifer, Artemia nauplii and commertial micro diet were investigated the changes of lipid content, fatty acid composition and vitamin E content in whole body with growth stages in order to compare with those of the wild one. The results obtained are as follows. 1) Lipid and vitamin E contents of the cultured larvae were higher than those of the wild one. 2) Clear differences of fatty acid composition with growth stages, especially 18: 2n-6 and 22 : 6n-3, were recognized between the wild and cultured olive flounder larvae. 3) Changes of lipid content, fatty acid composition and vitamin E content were found to be affected by dietary composition given to fish. 4) The wild olive flounder larvae were found to obtain natural live foods containing of low lipid content and high concentration 22: 6n-3 based on the fatty acid composition of the fish.