• 한국연소학회:학술대회논문집
• /
• 2015.12a
• /
• pp.275-275
• /
• 2015

• Journal of the Korean Ceramic Society
• /
• v.43 no.3 s.286
• /
• pp.148-151
• /
• 2006

In order to examine the process parameters for the vitrification of Low and Intermediate Level radioactive Waste (LILW) generated from nuclear power plants, measurements of several melt properties was performed for four selected glasses containing simulated waste. Electrical conductivity and viscosity were determined at temperatures ranging from 1123 to $1673^{\circ}C$. The temperature dependences of both properties in the molten state showed a similar behavior in which their values decrease as the temperature increases. The values of the electrical conductivity and viscosity at a temperature of 1423K adopted in an induction cold crucible melter process were $0.27{\sim}0.42$ S/cm and $9.8{\sim}42$ dPas, respectively.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.298-298
• /
• 2006

There has been much interest in incorporating nanoscale voids into dielectric materials in order to reduce their k value, and thus in producing low-k porous interdielectric materials. One approach to the development of low-k dielectric materials is the templated polycondensation of organosilicate precursors in the presence of a thermally labile, organic polymeric porogen. The other is SiOCH films have low dielectric constant as well as good mechanical strength and high thermal stability through PECVD. In this article we explore the nanopore generation mechanism of organosilicate film using star-shape porogen and SiOCH film using bis-trimethylsilylmethane (BTMSM) precursor.

• Journal of the Korean Society of Safety
• /
• v.17 no.1
• /
• pp.6-10
• /
• 2002

This paper presents the impact behavior and damage of laminated composite plates subjected to low-velocity impact. For this purpose, a pendulum impact test for impact behavior and C-scan for impact damage are done. Test materials are carbon/epoxy laminated composite plates and stacking sequences $[0/90_4\;[0/45_2/-45]_s,\;[0/45/-45/90]_s$ and [0/26/51/77/-77/-51/-26/0].

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.355-356
• /
• 2006

WC-TiC-TaC binderless cemented carbide was oxidized under low partial pressure of oxygen (50ppm) at 873K for 1 to 20 h. Surface roughness was measured using atomic force microscope, and effect of TiC amount on oxidation behavior of the carbide was investigated. WC phase was oxidized more easily than WC-TiC-TaC solid solution phase. With an increase in TiC amount, WC-TiC-TaC phase increased and the oxidation resistance of the carbide increased.

• Korean Journal of Materials Research
• /
• v.24 no.10
• /
• pp.520-525
• /
• 2014

Effects of Cu and B on effective grain size and low-temperature toughness of thermo-mechanically processed high-strength bainitic steels were investigated in this study. The microstructure of the steel specimens was analyzed using optical, scanning, and transmission electron microscopy; their effective grain size was also characterized by electron back-scattered diffraction. To evaluate the strength and low-temperature toughness, tensile and Charpy impact tests were carried out. The specimens were composed of various low-temperature transformation products such as granular bainite (GB), degenerated upper bainite (DUB), lower bainite (LB), and lath marteniste (LM), dependent on the addition of Cu and B. The addition of Cu slightly increased the yield and tensile strength, but substantially deteriorated the low-temperature toughness because of the higher volume fraction of DUB with a large effective grain size. The specimen containing both Cu and B had the highest strength, but showed worse low-temperature toughness of higher ductile-brittle transition temperature (DBTT) and lower absorbed energy because it mostly consisted of LB and LM. In the B-added specimen, on the other hand, it was possible to obtain the best combination of high strength and good low-temperature toughness by decreasing the overall effective grain size via the appropriate formation of different low-temperature transformation products containing GB, DUB, and LB/LM.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.4
• /
• pp.345-351
• /
• 2011

Two feeding trials were conducted to investigate the optimum feeding rates in juvenile olive founder Paralichthys olivaceus fed practical expanded pellet(EP) containing 58.1% crude protein, 10.7% crude lipid, and 10.8% ash at low and high water temperatures. In the first experiment, triplicate groups of 15 fish with average weight of 7.7 g were fed at one of seven feeding rates(0, 1, 1.5, 2, 2.25, or 2.5% of body weight/day or to satiation) for 4 weeks at low water temperature. In the second experiment, quadruplicate groups of 20 fish with average weight of 5.5 g were fed at one of eight feeding rates(0, 3, 3.5, 4, 4.25, 4.5, or 4.75% of body weight/day or to satiation) for 4 weeks at high water temperature. Based on growth performance, we estimated that the optimum feeding rates for juvenile olive flounder were 1.97-2.51% and 4.82-6.36% of body weight/day at low and high water temperatures, respectively.

• Journal of the Korean Ceramic Society
• /
• v.46 no.4
• /
• pp.413-418
• /
• 2009

Glass systems based on Ca, Sr, Ba, and Zn modified alumino-boro silicates were investigated in order to improve the dielectric and mechanical properties of a typical LTCC (low temperature co-fired ceramic) which was developed for high frequency highly-integrated modules. The glass was prepared by a typical melting procedure and then mixed with cordierite fillers to fabricate glass/ceramic composite-type LTCC materials. The amount of cordierite filler was fixed at 50 volumetric%. For an optimal glass composition of 7.5% CaO, 7.5% BaO, 5% ZnO, 10% $Al_2O_3$, 30% $B_2O_3$, and 40% $SiO_2$ in mole ratio, the resultant LTCC composite showed a dielectric constant of 5.8 and a dielectric loss ($tan{\delta}$) of 0.0009 after firing at $900^{\circ}C$. An average bending strength of 160MPa was obtained for the optimal composition.

• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.3 s.32
• /
• pp.9-15
• /
• 2004

We investigated the electrical properties of copolymer low-k materials that are compromised of the PMSSQ(Poly Methyl Silsesquioxane)-based matrix with the BTMSE (Bis Tri Methoxy Silyl Ethane) additives. We manufactured MIS-type test samples using the copolymer as the insulator and measured their leakage current and failure time by means of the BTS (bias-temperature-stress) test. The failure time was observed to decrease drastically when the porosity of the copolymer was increased over $30\%$. From the measurement of failure time with respect to temperature. the activation energy of Cu drift through the copolymer was calculated to be 1.51 eV.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1437-1440
• /
• 2008

In this paper, we mainly deal with metallic electrode materials and patterning processing of plasma display panels. We focus on the recent development status, where low cost and high performance electrode materials such as Ag-based single-layered bus, low cost-in-use and anti-migration address electrodes are briefly introduced. The technological trends and further works on novel electrode materials and processing are also discussed.