http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Co-Doped Willemite 파란색 안료의 합성과 생성기구
황동하,한경섭,이병하,Hwang, Dong-Ha,Han, Kyong-Sop,Lee, Byung-Ha 한국세라믹학회 2010 한국세라믹학회지 Vol.47 No.6
Turquoise blue pigment of Vanadium-zircon blue (DCMA number 14-42-2), which was already commercialized, was stable to be reproduced but insufficient to give strong blue. However, it possible to obtain more intense blue by partially substituting cobalt ions into the willemite($Zn_2SiO_4$) lattice classified into DCMA number 7-10-2 for blue ceramic pigment. By the composition of willemite $Co_xZn_{2-x}SiO_4$(X=0.01, 0.03, 0.05, 0.07, 0.09 mole), this study used reagent grade zinc oxide, cobalt oxide and silicon dioxide as starting materials, carrying out the synthesis with solid reaction method by adding $H_3BO_3$ as a mineralizer. The firing temperature was between $1200^{\circ}C$ and $1400^{\circ}C$. The characteristics of synthesized pigment were analyzed by X-ray diffraction, Raman spectroscopy and SEM and the characteristics of color tones were analyzed by UV-Vis spectroscopy and CIE-$L^*a^*b^*$ measurement. As a result, the optimal composition was $Zn_{1.95}Co_{0.05}$ with 1wt% of $H_3BO_3$ as a mineralizer and firing condition was $1350^{\circ}C$/3 h. $L^*a^*b^*$ value was 29.25, 41.03, -59.93 for on glaze pigment and 37.03, 36.41, -60.03 for under glaze pigment.
ZrTiO<sub>4</sub>계 Gray 안료 합성과 형성기구
황동하,이병하,Hwang, Dong-Ha,Lee, Byung-Ha 한국세라믹학회 2012 한국세라믹학회지 Vol.49 No.1
Attempts were made to develop a stable gray pigment at reducing atmosphere, substituting Ti in $ZrTiO_4$ with Mn, Fe, Co and Cu The pigment synthesized at $1300~1500^{\circ}C$ by solid state method with the composition of $ZrTi_{1-x-y}A_xB_yO_4$ (x = y = 0.005, 0.015, 0.035, 0.055, 0.075, 0.095, 0.115, 0.135, 0.155, 0.175 and 0.195 mole, A = Mn(III), Fe(III), Co(II, III) and Cu(II) (chromophores), B = Sb (counterion). The pigments were fired at $1400^{\circ}C$ for 3 h with substitute amount changes of Mn, Fe, Co and Cu to $ZrTiO_4$ crystals, and analyzed by Raman spectroscopy to figure out substitute limits. Results indicated 0.035 mole for Mn, 0.115 mole for Fe, 0.015 mole for Co and 0.015 mole for Cu as substitute limits, respectively. Figs. 1, 2, 3, and 4 represent each substitute pigments of Mn, Fe, Co and Cu. Synthesized pigment was applied to a lime and a lime-magnesia glaze at 7 wt% each, and fired at reducing atmosphere of $1240^{\circ}C$, soaking time 1h. Gray color was obtained with CIE-$L^*a^*b^*$ values at 44.55, -0.65, 1.19(Mn), 40.36, -0.90, 0.30(Fe), 42.63, -0.03, -1.49(Cu) and -40.79, -0.28, -0.91(Co), respectively.
독·소 불가침 조약 ( 1939. 8. 23 ) 의 성립 - 소련 측의 동기 분석을 중심으로 -
황동하(Dong Ha Hwang) 한국서양사학회 2001 西洋史論 Vol.68 No.1
This article sets out to analyse some points as follows. When Germany decided to attack on Poland in the spring of 1939, the Western powers wanted to restrict German aggression. The British and French response was to secure Polish borders. On the other hand the Soviets proposed a triple alliance, which protected peace to all the states between the Baltic and Black Seas. Both sides had sharp differences on the national security problems of the Eastern Europe. The triple alliance negotiations started with much considerations. The key issues were over guarantees of the Baltic states and negotiations for a military convention tied to the political agreement. The triple alliance negotiations dragged on, haggling over endless wordings of these problems. From the Soviet`s point of view, the experience of negotiating with the British and French had not exactly been encouraging. They had dragged their feet throughout the triple alliance negotiations. In this atmosphere the Soviet government began to contemplate the possibility of an agreement with Nazi Germany. From about the mid-April Germany let the Soviet government know that they were ready to improve relations. The Soviets had suspected that German`s approaches were the part of some kind of petit jeu aimed at disrupting the triple alliance negotiations. However it was not by the end of July that the Soviets were seriously considering German`s approaches. From 11th August, therefore, the Soviets developed `double diplomacy`. The triple alliance negotiations were interrupted because the Western allies could not guarantee that Rumania and Poland would allow Soviet troops to pass through their territory. The Soviets knew that in early August German diplomatic initiatives toward the Soviets became more pressing as German military preparations for an invasion of Poland became matured. It seems that the Soviet leadership up to the last minute did not chose its course, but simply kept its options open. By the middle of August, however, the international situation changed suddenly. The German war plans called for an invasion of Poland on August 17 and the Soviets knew it. Now the Soviets had to choose. While the triple alliance negotiations was brought to a deadlock over this problems, Germany offered a Soviet-German `condominium` in Eastern Europe. In the situation that the likelihood of reaching the triple alliance was uncertain, the Soviets had to avoid the impending war. That is, the Soviets might have the aim of avoiding a war with Nazi Germany in Eastern Europe while Britain and France stood on the sidelines. And so, the Soviets accepted Hitler`s offer. (Sookmyoung Women`s University)
황동하(Hwang Dong-ha) 가천대학교 아시아문화연구소 2010 아시아문화연구 Vol.19 No.-
The aim of this paper is to examine the Korean intellectual’s image of the Soviet Union during the Cold War eras through analysis of some writings on anti-communist ideologues. It has therefore been observed that Soviet regime marks the darkest age in the history of mankind as it bears witness to violence, poverty and nihilism. The attitude towards Soviet Union was far from objective. North Korea was portrayed as the national antagonist, deliberately emphasizing on the negative image of Soviet Union, North Korea in turn served as a suzerain state as it remains an allusion for South Korean government to be established on such perceptions. As such, the stand off between South and North Korea was led by Korean intellectuals whose discernment shaped their anticommunist ideology. At some point, these areas of thought interfered with sound judgment regarding the Soviet Union and the philosophical balance.
PBM(Population balance model)을 이용한 고로 내 입자 적하 거동 해석
황동하(D.H. Hwang),백제현(J.H. Baek),최응수(E.S. Choi),이상호(S.H. Lee) 한국전산유체공학회 2011 한국전산유체공학회 학술대회논문집 Vol.2011 No.11
Analysis of the inside of the blast furnace is needed to solve the decreasing of the productivity and to control the ventilating and discharging. Blast furnace is composed of various materials ? burning gas, liquid iron and solid particle, so-called multiphase filed. This paper presents a foundational multiphase numerical simulation with mathematical governing equation and PBM(population balance model) represented by particle size distribution to calculate the number density of particles in liquid and solid mixture. Describing the behavior of the individual particles is, in essence, similar to describing the distributed properties, which is less complex. Size reduction rate is significant to analyze the macroscopic chemical/physical phenomena and results the change in particle size distribution, average particle size and total solid volume fraction.