이규화몰리브덴 고온발열체의 고온산화거동

서창열,장대가,심건주,조덕호,김원백,Seo, Chang-Yeol,Jang, Dae-Ga,Sim, Geon-Ju,Jo, Deok-Ho,Kim, Won-Baek 한국재료학회 1996 한국재료학회지 Vol.6 No.1

MoSi2 heating elements were fabricated by sintering of MoSi2 powders which were synthesized through SHS(Self-propagating high-temperature synthesis). Their high-temperature oxidation behavior in air through SHS(Self-propagating high-temperature synthesis). Their high-temperature oxidation behavior on air at 1000-1600$^{\circ}C$ was investigated through a high-temperature X-ray diffractomer and isothermal heating in a muffle furnace. The thermal expansion of MoSi2 and SiO2 was studied by measuring their lattice parameters on heating. The linear expansion coeffcient of MoSi2 along c-axis was about 1.5 times larger than that along a-axis showing a strong thermal anisotropy. Few $\mu\textrm{m}$-thick Mo5Si3 layer was found beneath SiO2 layer suggesting that The major reaction products would be SiO2 and Mo5Si3. The Si-rich bentonite resulted in the faster growth of MoSi2 grains probably by enhancing the mass transport when they are melted during high-temperature oxidation.

敎役者像의 硏究

徐昶烈 圓光大學校 1975 論文集 Vol.9 No.-

少太山 大宗師의 人間像 硏究

徐昶烈 圓光大學校 1976 論文集 Vol.10 No.-

The Venerable Sotesan(Founder of Won Buddhism) came out into the world in the violent time of the last peried of Ri-Dynasty, in which Korean people were suffering from domestic and foreign events, gradually forgetting the spiritual life during this time. He organized the Buddha Dharama Reserch society, upholding the slogan of "Develop our spiritual morality while the material civilzation is being developed." For several hundred years Ri-Dynasty was given up to the party conflicts, sinking into effeminacy, the contnol of central-government became weaker than any other past time, and the degree of official's extortion to the common people got to the highest level. Taking this advantage of the confusion, Japan invaded and entirely overruled all the country. At last Ri-Dynasty collapsed. The masses under the extremely troubled situation cannot be saved from wandering, and lost their common cause and national system. To these people, planting the courage and hopes, said the great Master Sotesan as followings. "As Mt. Diamond comes to be famous in the world, the Land of the Morning calm(Korea) is noted" "Recently some people have said that the world, which is in its last period, will be destroyed, but I do not believe that will happen.Doubtlessly, the world which has been without a sage for a long time is in its last period with justice and morality declining. A more civilized moral world is coming." "It masy be rather hard for ordinary people to forsee the future, but thoses who are able to foresee the civilized world have great pleasure." "To the mankind who experienced two world wars, and were trembling from fear, continued the great Master, saying, "Now we are in a world where the dark night is almost over and the sun is about to rise in the east...." The great Master Sotaesan was born a son of a Farmer in the south western part of the Korean Peninsula. After years of moral training and spirirual search, he attained self-enlightment, and made up his mind to deliver the world with the spirit of Buddhism based on I1-Won-Sang Truth. He himself already became the saint of the New world. The enlightment of the I1-Won-Sang Truth gave him a limitless power to establish the new great religious order, in which Buddha Dharma should be the central principle. He constructed the basis on which all other religions can be suprorted, practicing the principle of Won Buddhism as a future directional religion. He symbolized the ultimate truth by the I1-Won-Sang, throwing light upon the obvious truth that all the religions should coincide with each other. The two years before the literation of Korean from Japanese Occupation the great Master Sotaesan passed awey into Nirvana. He will be looked up to as a saint just as in his life time. Moreover he will be deeply admired as a eternal example of mankind who are searching for the truth, gool, and beauty. He was born a common people and in common life attained self-enlightment, and with great genorosity taugth his diciples, searching the meeing point of all the thoughts and religions. He will be forever in all Won Buddhists' memory.

MH전지용 $\textrm{ZrV}_{x}\textrm{Mn}_{1-x-y}\textrm{Ni}_{1+y}$ Laves합금의 결정구조

김원백,서창열,최국선,김인곤,Kim, Won-Baek,Seo, Chang-Yeol,Choe, Guk-Seon,Kim, In-Gon 한국재료학회 1997 한국재료학회지 Vol.7 No.3

아크용해로와 진공유도로를 사용하여 니켈-수소 전지의 음극용으로 주목받고 있는 AB2 타입의 ZrV /sub x/Mn/sub 1-x/Ni/sub 1.0/, ZrV/sub x/Mn/sub 0.8-x/Ni/sub 1.2/, ZrV/sub x/Mn/sub 0.6-x/Ni/sub 1.4/합금을 용해하였다. 이들 합금은 용해한 상태에서 C14과 C15의 혼합상을 갖는 것으로 나타났으며 합금조성 및 열처리에 따라 혼합상분율이 크게 변화하였다. 이들의 결정상 및 상분율은 합금원소들의 평균원자반경비(r/sub A//r/sub B)에 따라 결정되는 것으로 밝혀졌으며 특히 열처리한 합금의 경우에는 평균원자반경비가 1.254일때를 경계로 하여 두 상의 명확간 안정구역이 설정되었다. 가압한 분위기에서 아크용해한 경우 합금성분의 손실은 미미하였으나 진공유도로를 사용하여 용해한 경우 Mn이 다량 휘발감소하여 조성이 크게 변화하였다. The crystal structure of arc melted $ZrV_{x}Mn_{1-x}Ni_{1.0},\;ZrV_{x}Mn_{0.8-x}Ni_{1.2},\;ZrV_{x}Mn_{0.6-x}Ni_{1.4}$ alloys which are known to have AB2 type Laves structure was investigated. They had mixed phases of C14 and C15. The radius ratio ($r_{A}/r_{B}$) of atoms in A site to that of B site was found to be an important parameter in explaining the omposition dependence of the crystal structure The C15 structure showed a linear increase with the ratio in as-cast conditions. However, the annealed alloys revealed a definite ratio at which the stability of both phases are divided distinctly. The composition of the alloys could be closely controlled by maintaining the argon pressure in the chamber over 1 arm during arc melting. In contrast, the alloy ingot melted in VIM showed a significant loss of hln.

페리튬이온전지로부터 양극활물질인 LiCoO2의 합성

이철경,양동우,서창열 한국자원공학회 2002 한국자원공학회지 Vol.39 No.3

A process involving mechanical, thermal, hydrometallurgical, and sol-gel step has been applied to recover cobalt and lithium from spent lithium ion batteries and to synthesize LiCoO2 from leach liquor as cathodic active materials. Electrode materials containing lithium and cobalt could be concentrated with 2-step thermal and mechanical treatment. Hydrogen peroxide in 2 M HNO3 solution turned out to be an effective reducing agent by enhancing the leaching efficiency. Of many possible processes to produce LiCoO2, the amorphous citrate precursor process (ACP) has been applied to synthesize powders with a large specific surface area and an exact stoichiometry. When the precursor was calcined at 950oC for 24hr, purely crystalline LiCoO2 was successfully obtained. The particle size and specific surface area of the resulting crystalline powders were 20mm and 30cm2/g, respectively. The LiCoO2 powder was proved to have good characteristics as cathode active materials in charge/discharge capacity and cyclic performance. 재활용 일환으로 기계적, 열처리, 습식제련 및 sol-gel 공정을 제안하였으며, 폐전지 로부터 Co와 Li을 회수하고 침출액으로부터 양극활물질인 LiCoO2를 합성하여 특성을 분석하였다. 2단계 기계 적 처리 및 열처리로 전극물질을 분리 농축할 수 있었으며, 양극활물질로부터 질산만으로는 Co와 Li을 각각 40%와 80% 용해하였지만 환원제로서 과산화수소를 첨가하여 Co와 Li의 침출효율을 95% 이상으로 향상시킬 수 있었다. Amorphous citrate precursor(ACP) 법은 비표면적이 크고 정확한 당량비를 갖는 복합산화물 분말 제 조에 유리한 방법으로 본 연구에서도 ACP 법으로 평균입도와 비표면적인 각각 20mm and 30cm2/g 인 LiCoO2 단일상 분말의 제조가 가능하였다. 합성한 분말을 이용하여 반전지 셀을 구성하고 충방전 특성을 조사한 결 과, 성능이 우수한 양극활물질로 사용이 가능함을 확인하였다.

Zr기 $AB_2$ Laves Phase 합금(Zr-V-Mn-Ni)의 조성에 따른 결정구조와 방전 특성

김인곤,정원섭,장대규,서창열,김원백,Kim, In-Gon,Jeong, Won-Seop,Jang, Dae-Gyu,Seo, Chang-Yeol,Kim, Won-Baek 한국재료학회 1996 한국재료학회지 Vol.6 No.11

니켈-수소화물전지의 음극재료로서 주목을 받고 있는 다원계 Zr기 Laves 합금의 조성에 따른 결정구조, 방전특성등을 조사하였다. 전극은 아크 용해한 합금을 분쇄한 분말과 PVA를 다공성니켈 foam에 충진하여 제작하였고 충방전시험은 6M KOH 용액중에서 수행하였다. 대상 합금은 ZrNi2를 기본조성으로 하여 이중 Ni의 일부를 V, Mn, Cr, Mo 또는 W로 치환한 삼원계 및 사원계 합금이었다. 이들 합금의 충방전 실험결과 ZrV0.5Mn0.5Ni1.0의 경우가 260 mAh/g로 가장 높은 방전용량을 나타내었다. 이 합금의 방전용량은 방전전류밀도의 영향을 크게 받았으며 10 mA/g과 200mA/g의 방전전류에서 각각 300mAh/g와 150mAh/g이었다. 이 합금을 110$0^{\circ}C$에서 열처리한 경우 저율방전시에는 방전용량의 변화가 거의 없었으나 수소의 확산이 율속이 될 것으로 생각되는 고율 방잔시에서는 방전용량이 현저하게 감소하였다. 이러한 현상은 열처리에 의해 수소의확산을 용이하게 해주는 격자결함이 감소하기 때문이 아닌가 생각된다.

오산화바나듐(V2O5)의 건식 정제에 관한 기초 연구

김병수,류태공,장한권,서창열,유정현,최지혁,조성욱,길대섭 한국자원공학회 2021 한국자원공학회지 Vol.58 No.1

A fundamental study on the volatilization purification method, a pyrometallurgical purification technology, was carried out to examine the removal of impurities from vanadium pentoxide (V2O5). From the thermodynamic analysis, it was expected that impurities contained in V2O5 could be removed into the gas phase while holding it at temperatures over 300°C for P2O5 and at over 600°C for NaOH and KOH, because of their high vapor pressures. Experiments were carried out in the temperature range of 600–1,100°C and a holding time range of 15–60 min under atmospheric and reduced pressures. The range of reduced pressure was 7.9×10 -2 –1.1×10 -1 atm under an argon atmosphere. By comparing the thermodynamic analysis with the experimental results, it was verified that impurities such as SO3, P2O5, NaOH, and KOH were effectively removed from V2O5 regardless of the pressure conditions of the furnace. At the optimum conditions, V2O5 with a purity of 99.6 wt% was manufactured from V2O5 with a purity of 99.2 wt%. 본 연구에서는 오산화바나듐(V2O5)로부터 불순물을 제거하기 위한 건식정제 공정법 중의 하나인휘발정제 방법에 대한 기초연구를 수행하였다. 열역학적 분석결과 오산화바나듐에 함유된 P2O5 불순물은 300°C 이상에서 NaOH와 KOH 같은 불순물은 600°C 이상에서 증기압이 높아 기상으로 휘발 제거가 가능할 것으로 분석되었다. 실험은 대기 분위기와 감압 분위기에서 휘발온도 600 – 1000°C, 유지시간 15 – 60분으로 변화시키면서 수행되었다. 감압은 아르곤 분위기에서 7.9×10 -2 – 1.1×10 -1 기압으로 조절하였다. 열역학적 분석결과와 실험 결과를 비교함으로써 SO3, P2O5, NaOH, KOH 같은 불순물이 로내 압력 조건에 상관없이 효과적으로 오산화바나듐으로부터 제거된다는 것이 확인되었다. 최적 조건에서 99.6 wt% 순도를 갖는 오산화바나듐이 99.2 wt% 순도를 갖는 오산화바나듐으로부터 제조되었다.

과활동성방광을 동반한 전립선비대증 증상 환자에서 얼음물검사의 유용성

서창덕,양대열,김하영 대한비뇨의학회 2005 Investigative and Clinical Urology Vol.46 No.8

Purpose: A video-urodynamic study is known as the most accurate test to differentiate between benign prostatic hyperplasia(BPH) with overactive bladder and detrusor instability but requires expensive equipment and an expert technique, so is not commonly available. We performed a video- urodynamic study and ice-water test which is easily performed for the diagnosis of a neurogenic bladder in the patients with symptomatic BPH associated with overactive bladder and compared the results. Materials and Methods: The video-urodynamic study using a 10-Fr triple lumen urodynamic catheter was performed in 36 patients with symptomatic BPH associated with overactive bladder that had frequency, weak stream, nocturia, urgency, urge incontinence, dysuria and no clinical neurogenic defect. After the video-urodynamic study, the ice-water test was performed by instilling 4oC sterilized water through a catheter at 200ml/ min in the supine position. The volume instilled was about 30% of the bladder capacity. The ice-water test was positive if there was an efflux of water around the catheter during or after water instillation. Results: Thirty two of the 36 symptomatic BPH patients with an overactive bladder were negative on the ice-water test. All 32 patients who had a negative ice-water test were BPH with overactive bladder on the video- urodynamic study. Four of the 36 symptomatic BPH patients with an overactive bladder were positive on the ice-water test. Two of the 4 patients who had a positive ice-water test were BPH with overactive bladder and the other two were detrusor instability on the video-urodynamic study. Conclusions: Therefore, in case of a positive ice water test, a video-urodynamic study is needed to differentiate between BPH with overactive bladder and detrusor instability in patients with symptomatic BPH associated with overactive bladder.

나노결정형 Zr₅₇V₃₆Fe₇ 게터합금의 수소흡수특성

박제신,서창열,김원백,Park Je-Shin,Suh Chang-Youl,Kim Won-Baek 한국분말야금학회 2005 한국분말재료학회지 (KPMI) Vol.12 No.6

The hydrogen sorption speed of $Zr_{57}V_{36}Fe_7$ nanocrystalline and amorphous alloys was evaluated at room temperature. Nanocrystalline alloys of $Zr_{57}V_{36}Fe_7$ were prepared by planetary ball milling. The hydrogen sorption speed of nanocrystalline alloys was higher than that of the amorphous alloy. The enhanced sorption speed of nanocrystalline alloys was explained in terms of surface oxygen stability which has been known to retard the activation of amorphous alloys. The retardation can be reduced by formation of nanocrystals, which results in the observed increase in sorption properties.

An XPS study of titanium-chromium nitride (Ti,Cr)N nanopowder prepared by heat treatment in flowing nitrogen gas

송경선,서창열,조성욱,배종성,손인진,김원백 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.3

The electrical wire explosion of Cr-coated Ti wires produced nanosized particles consisting of various phases such as β(Ti,Cr),α-Ti, TiCr2 and TiN. The particles were heat treated at 800 οC ~ 1100 οC in flowing N2 gas in an effort to synthesize a ternary nitride, (Ti,Cr)N. An X-ray diffraction study revealed that they transformed to a single-phase (Ti,Cr)N during heating at 1100 οC for 1 h. An X-ray photoelectron spectroscopy (XPS) was used to examine the electronic configurations of Ti, Cr, and O after nitriding at various temperatures. After heating at 800 οC, the metallic Cr 2p peak vanished in accord with the disappearance of the β(Ti,Cr) phase confirmed by XRD. The inspection of XPS spectra suggested that the electronic configuration of (Ti,Cr)N is identical to that of TiN. The metal to nitrogen ((Ti + Cr) / N) ratio decreased with the nitriding temperature becoming 1 after heating at 1100 οC. XPS quantification revealed that the ternary nitride had the composition of (Ti0.6Cr0.4)N.