DIE FLAMMENLA¨NGE VON KONZENTRISCHEN BRENNSTOFF-LUFTSTRAHLEN

Lim, Eung Keuk 서울대학교 1970 서울대학교 論文集 Vol.21 No.-

共心 젯트(jet) 火炎의 길이에 關한 硏究에 있어서 개스가 나오는 內管의 지름은 4㎜와 8㎜로 하고 空氣가 나오는 外管의 지름은 空氣 對 개스의 比를 Paramter(λ)로 하여 λ의 값을 달리 함으로써 決定하고 또 개스의 速度를 44m/sec에서 110m/sec까지 變하는데 λ의 값에 따라 空氣의 量을 決定하고 그들에 對한 火炎의 길이를 測定하는 데는 共心中心軸에서 燃燒개스를 分析하였다. 이들의 값은 大氣中과 샤프트 킬른속에서 얻을 수 있었는 데 大氣中에서는 寫眞을 찍어 分析法과 比較하였다. 그 結果 共心 젯트 火炎의 安定性은 λ의 값이 커 감에 따라 작아 지지만 샤프트·킬른속에서의 火炎은 大氣中의 것 보다도 安定하지 못하였다. λ의 값을 變함에 따라 燃燒의 消火의 曲線은 急커어브를 이루었는데 이것은 火炎의 幅이 좁아 지고 짧게 된 것 卽 火炎의 부피 單位當 옮겨진 熱量이 급작히 많아 졌다는 것을 뜻하는 것이다. 大氣中에서 燃燒하는 火炎의 길이는 λ와 더불어 直線的으로 減少하지만 샤프트 킬른속에서 燃燒하는데 火炎의 길이는 λ=0.1와 0.2일 때 더 길어 지고 λ=0.3 以上에서는 大氣中에 燃燒하는 火炎에 比例하여 짧아 지고 있다. 개스 出口의 速度가 커지고 버너 지름이 커짐에 따라 火炎의 길이도 增加하지만 이 길이는 길이를 개스管의 지름으로 나누었기 때문에 無次元으로 나타낸다. 이 것은 Reynolds數의 依存性을 證明하는 것이다. 또 寫眞으로 찍은 길이와 共心軸에서의 燃燒개스 分析으로 얻은 火炎의 길이는 잘 맞는 다는 것을 알 수 있다. 本硏究는 火炎의 길이에 關하여 各種의 버너의 構造로서 廣範圍하게 다루므로써 燃料와 空氣의 共心 젯트 火炎의 길이를 測定하는 데 必要한 Parameter에 關한 槪要를 論述하고 있다.

시멘트의 소성

임응극,Lim Eung Keuk 한국시멘트협회 1973 시멘트 심포지움 Vol. No.

A historical review of burning processes on cement manufacture has been made regarding specially to heat efficiency. In addition to these processes, two examples of stoichiometric calculation dealing with combustion such as air fuel ratio and excess air h

Effect of Composition Variation and Particle Size of a Bristol Glaze

임응극,Eung Keuk Lim Korean Chemical Society 1963 대한화학회지 Vol.7 No.2

브리스톨釉藥을 콘 5, 8, 11 番으로 燒成했을때 나타나는 狀態에 對한 組成變化와 粒度의 京鄕을 硏究하여, 밝은 半艶消 또는 艶消釉藥을 얻을 수 있었다. 卽 各 釉藥에 對한 熱成範圍, 曲强度 및 光澤, 平滑性, 乳白度, Eggshelling, 龜裂, Pinholing, Crawling 等에 對한 因子를 決定하므로서 얼마나, 珪酸, 알카리, 石灰를 變化시켜 實際 使用可能한 良好한 釉藥을 얻었다. 製造된 브리스톨釉藥은 最低 콘 5番부터 11번 또는 그 以上에서 긴 熟成範圍를 나타냈다. Crawling의 傾向에 있어서는 ZnO 量이 增加될때 特히 甚했으나, $Al_2O_4:\;SiO_2$의 比가 크고 ZnO 量이 많을때 乳白度가 顯著하였다. 釉藥의 粒子를 가늘게 하면 熱成이 잘되나 微粒이면 Crawling이 커진다. 釉藥두께를 增加해도 Crawling 傾向이 커진다. A study was made of the effect of composition changes and particle size on appearance of raw bristol glazes fired at cones 5, 8, and 11. Alumina and silica, alkali and lime variations were made to get some of the more promising glazes determining maturing ranges, modulus of rupture, and other factors such as gloss, smoothness, opacity, eggshelling, crazing, pinholing and crawling for each glaze. Modulus of rupture was measured for the glazes fired at only cone 11.

Dielectric Behavior of Steatite Body

임응극,Eung Keuk Lim Korean Chemical Society 1963 대한화학회지 Vol.7 No.2

粘土鑛物과 滑石과의 關係에 對한 正確한 報告가 거의 없어. 이에 對한 磁器化溫度範圍 및 電氣的絶緣性과 粘土含量의 關係를 究明하였다. 스테아타이트素地의 製造에 使用한 原料는 國産 滑石, 粘土, 長石, 硅石等이며, 吸水率, 燒成線收縮率을 測定 檢討하고, 또 磁器化된 素地들의 電氣的絶緣性을 測定하였다. 그 結果 磁器化溫度範圍는 재겔錐 1乃至 3番內에 있었으며 $MgCO_3$를 添加함에 따라 燒成收縮은 크게 일어났으나, 粘土含量이 20% 以下였을 때는 磁器化溫度範圍가 增大되었다. 耐熱性은 全般的으로 良好하였으며 粘土量을 增加시킴에 따라 膨脹率, 誘電體力率, 絶線耐性은 增加하고, 體積固有抵抗은 減少하였다. A review of the literature is cited. Little exact information exists on the relation between clay materials and talc. The raw materials which are used in making steatite body consist of talc, clay, feldspar, and flint mined in Korea. The percentage absorption and linear burning shrinkage are measured and then discussed. The vitrified bodies were used in measurement of dielectric properties. The method of measurements for dielectric properties are described too.

국내 점토광물의 특성연구

임응극,박순자,정수진,김환,Lim, Eung-Keuk,Park, Soon-Ja,Chung, Su-Jin,Kim, Hwan 한국세라믹학회 1980 한국세라믹학회지 Vol.17 No.1

Mineral identifications on halloysite in Hadong-Sancheong area and the halloysite bearing clay ii Yeoju, Yesan and Hampyeong-Muan area are carried out by the method of X-ray diffraction, electron microscopy and DTA. Chemical composition of the above minerals are analyzed by means of X-ray-fluorescence. Refractoriness are also measured by refractoriness tester. A standard diagram for quantitative analysis of halloysite is given.

용융금속에 의한 Ceramic Oxides에서의 Wetting에 관한 연구

이석권,임응극,김환,Lee, Seok-Keun,Lim, Eung-Keuk,Kim, Whan 한국세라믹학회 1983 한국세라믹학회지 Vol.20 No.4

The Wetting of fusion cast $Al_2O_3$ brick and $Al_2O_3 -ZrO_2$ brick by liquid Ag was studied by the sessile drop technique in Ar atmosphere. In this experiment the specimens were photographed per 2$0^{\circ}C$with increasing temperature from 96$0^{\circ}C$ melting point of Ag. And the method of photographing was carried out by shadow technique. The cosine of the contact angle increased linearly with increasing temperature in both systems. And the relation between the cosine of the contact angle and the temperature was Cos$\theta$=1.132+$0.75{\times}10^{-3}T$ for $Al_2O_3$ brick and Cos$\theta$=-1.706+$1.125{\times}10^{-3}T$ for $Al_2O_3 -ZrO_2$ brick In both systems the contact angle decreased as the surface of substrate became smoother. The work of adhesion which was 503.5ergs/$cm^2$ for $Al_2O_3$brick and 393.6 ergs/cm2 for $Al_2O_3 -ZrO_2$ brick at 96$0^{\circ}C$ increased parabolically with increasing temperature in both system.

부분 안정화 지르코니아의 파괴거동

김환,임은극,고정하,황규홍,Kim, Hwan,Lim, Eung-Keuk,Koh, Jeong-Kyu,Hwang, Kyu-Hong 한국세라믹학회 1984 한국세라믹학회지 Vol.21 No.3

The effect of tetragonal $ZrO_2$ phase on the mechanical behavior in 7 mole% calcia partially stabilized zirconia has been studied. The $ZrO_2$ powder containg 7 mole% CaO prepared by Hot Petroleum Drying Method calcined at 80$0^{\circ}C$ for 1 hour was nearly 100% tetragonal but as the calcining temperature increased certain amount of monoclinic phase appeared. The sintered specimen at 1$700^{\circ}C$ for 5 hours was aged at 130$0^{\circ}C$ for 0, 24, 48, 72 hours. X-ray diffraction data showed that in the aged specimen monoclinic tetragonal and cubic phase coexisted. The Kc value of aged specimen for 48 hr was about 4.5MN/m3/2 much greater than unaged sample. But aged for 72 hr the KiC value was decreased. The increasing of toughness in PSZ is based on the Stress-Induced Phase Transformation that is metastable tetra-gonal $ZrO_2$ changes t stable monoclinic phase within the stress field of crack and the mechanical fracture energy absorption is occured But in this case due to certain amount of tetragonal phase transformed to monoclinic phase during cooling the microcrack effect by transformation also considered. Trerefore both Stress-Induced Phase Transformation and inclusion induced microcracking effect contrbute to the increase of fracture toughness of 7 mole% CaO-$ZrO_2$ containing monoclinic and tetragnola phase simulataneously.

Studies on the Bituminization Process of Radioactive Liquid Waste[I]

Lee, Sang-Hoon,Chun, Kwan-Sik,Lim, Eung-Keuk Korean Nuclear Society 1975 Nuclear Engineering and Technology Vol.7 No.3

알카리로 처리한 국산 blown asphalt를 사용해서 방사성 폐액을 180-20$0^{\circ}C$ 범위 내에서 고화처리한 것이 산처리 한것보다 좋은 결과를 얻었으며, 방사선 조사선량이 4.0$\times$$10^{7}$ rad까지도 안정된 고화체로 존재하고 있다. 한편 40wt%의 고형분이 함유되어 있는 $^{137}$Cs-asphalt 고화체의 증류수에 의한 $^{137}$Cs의 용출율이 8.27$\times$$10^{-4}$ g/$\textrm{cm}^2$-day 인데 반하여 $^{90}$ Sr은 낮았으며, 일반적으로 증류수보다 해수때가 또한 pH가 증가함에 따라 용출율은 낮아진다. Immobilization of the second-cycle radioactive liquid wastes from a Purex process was developed with the blown asphalt (manufactured by Kukdong Shell Oil Company Ltd) to eliminate the possibility that the radioactive materials will be redispersed into the environment. Attempts to incorporate these wastes directly into the asphalt martrices without any pretreatment were not successful, as it was observed that the sulphuric acid in the waste oxidised the asphalt. Hence, the waste was treated with caustic soda and made alkaline prior to bituminization, so that it was found that this pretreatment made the waste compatible to the asphalt matrices. The pure blown asphalt samples irradiated with doses of 4.0$\times$10$^{7}$ rad showed no evidence of volume increase. The suitable temperature for incorporation of the alkaline wastes into blown asphalt was 180-20$0^{\circ}C$. The Products containing 50 wt% salts represented the following good properties viz., volume reduction (about 1.4), homogeneity, teachability etc. During the period of 131 day $s^{l37}$Cs from products containing 40wt% salts was leached at rates ranging from 2.70$\times$10-4 to 8.27$\times$10-4g/cm2_day but the rate for $^{90}$ Sr was lower by one to two orders of magnitude by distilled water. The leaching rates for $^{137}$ Cs and $^{90}$ Sr by sea water were slightly lower than by distilled water. Both of the leaching rates decreased with increasing pH.H.

$Y_2O_3-ZrO_2$를 $Al_2 O_3$ 매트릭스에 분산시 응력 유기 상변태의 효과

이태근,임응극,김환,Lee, Tae-Keun,Lim, Eung-Keuk,Kim, Hwan 한국세라믹학회 1985 한국세라믹학회지 Vol.22 No.1

The effect of stress induced phase transformation on $Al_2 O_3$ matrix dispersed with $ZrO_2-Y_2O_3$ has been studied. In order to determinate the mechanical properties three $Al_2O_3-ZrO_2$ composite series containing 1, 3 and 5 mole% $Y_2O_3$ were prepared. The starting materials were $Al_2O_3$ and $ZrO_2-Y_2O_3$ which was prepared from the aqueous solution of high purity $YCl_3$.$6H_2O$ and $ZrOCl_2$.$8H_2O$. Powder mixtures of $Al_2O_3-ZrO_2$ containing $Y_2O_3$ have been prepared by ball-milling with methanol and the samples were formed by isostatic press and sintered at 150$0^{\circ}C$ for 2hrs. After sintering. the specimens were polished for mechanical determination. The relative density of sintered specimens were also measured. It was found that the addition of 1, 3mole% to {{{{ { ZrO}_{2 } }} allowed full retention of the tetragonal phase in $Al_2O_3-ZrO_2$ but partially stabilized zirconia (PSZ) was produced by additions of 5 mole% $Y_2O_3$.The critical stress-intensity factor KIc of $A_2O_3-ZrO_2$ (containing 1 mole% $Y_2O_3$) composite materials increased with increasing $ZrO_2$ content, The maximum value of KIC=7Mn/$m^3$/2 at 20 mole% $ZrO_2$ exhibited about twice that of the $Al_2 O_3$ The modulus of rupture exhibited a trend similiar to KIC The maximum value of MOR was 580MN/m2. As the amount of Y2O3 increase it was observed that the maximum of KIC and MOR decreased : Additions of 3 mole% $Al_2O_3$ $Y_2O_3$ allowed the maximum of KIC 6MN/$m^3$/2 MOR 540MN/$m^2$ at 15 mole% $ZrO_2$ additions of 5 mole% $Y_2O_3$ allowed the maximum of KIC 5MN/$m^3$/2 MOR 410MN/$m^2$ at 10 mole% $ZrO_2$.

Studies on the Bituminization Process of Radioactive Liquid Waste[I]

Lee, Sang-Hoon,Chun, Kwan-Sik,Lim, Eung-Keuk Korean Nuclear Society 1975 Journal of The Korean Nuclear Society Vol.7 No.3

알카리로 처리한 국산 blown asphalt를 사용해서 방사성 폐액을 180-20$0^{\circ}C$ 범위 내에서 고화처리한 것이 산처리 한것보다 좋은 결과를 얻었으며, 방사선 조사선량이 4.0$\times$$10^{7}$ rad까지도 안정된 고화체로 존재하고 있다. 한편 40wt%의 고형분이 함유되어 있는 $^{137}$Cs-asphalt 고화체의 증류수에 의한 $^{137}$Cs의 용출율이 8.27$\times$$10^{-4}$ g/$\textrm{cm}^2$-day 인데 반하여 $^{90}$ Sr은 낮았으며, 일반적으로 증류수보다 해수때가 또한 pH가 증가함에 따라 용출율은 낮아진다.