Aromatic Disulfide를 이용한 Sulfenimine의 합성

丁國聲,朱東駿 慶熙大學校 1989 論文集 Vol.18 No.-

The method used for the preparation of sulfenimines is condensation of a sulfenamide with aldehydes or ketones, and oxidation of the sulfenamides and reaction of aromatic thiols with N-chloro-p-quinone imine, condensation of aromatic disulfides, metal, ammonia and aldehydes or ketones. Several metal ions such as silver, mercury, zinc, copper, cadmium, tin, and lead were employed as catalysts. Among metal ions, silver was superior to other metal catalysts in preparing sulfenimines resulting in high yield. Using the similar procedure, various sulfenimines from α-keto ester or α-keto acid were synthesized. Comparing the results of this study with the result from aldehydes or ketones revealed that steric factor might play an important role in the synthesis of sulfenimines.

금속응고 및 기계화 합금에 의한 Al-Fe-Cr합금의 미세구조

林鐘國 忠州大學校 1997 한국교통대학교 논문집 Vol.32 No.1

지금까지 급냉응고한 알루미늄 분산상에 대한 미세조직은 많은 연구가 진행되었으나 기계합금 공정후 미세조직에 대한 연구는 거의 찾아 볼 수 없었다. 급냉응고후 기계화 합금공정을 거처 제조된 Al-Fe-Cr합금은 고온에서 비교적 안정한 미세조직을 보이고 있으며 매우 큰 탄성계수를 갖는다. 급냉응고만을 실시한 분말과 비교해 볼 때 기계화 합금은 매우 미세하고 균일한 조직을 보이고 있으며, 열적으로도 기계화 합금과정에서 더 많이 생성된 Al₂O₃ 때문에 매우 안정한 미세구조를 보여 주고 있다. 350℃까지 열처리한 분말과 압출재는 비교적 우수한 열적안정성을 보여주고 있으며, 350℃이상에서는 급격한 조대화 경향을 보여 주고 있다. The most important advancement in the mechanical alloy of aluminium dispersion alloys has occurred in the aluminium transition metal alloy system and in process development. The low diffusivities of the transition metals and oxides in aluminium and high elastic modulus of the intermetallics in these systems result in microstructures having combined properties of high strength and thermal stability. Because the coarse and inhomogeneous particles which were produced by only atomized have deleterious effect on strength, control of composition of Fe, Cr in aluminium and introduction of mechanical alloying must be exercised to limit the volume fraction of such coarse and inhomogeneous phases. Microstructures resulting from atomizing and mechanical alloying generally contain the features of dendrite with no secondary arm and eutectic morphologies on a much finer scale compared with only atomizing, and depend greatly on the particle volume through high undercoolng and high ball mill energy. The microstructures of the only atomized Al-9.45wt% Fe-4.45wt%Cr powders are extremely inhomogeneous, but these of atomized and mechanically alloyed powders within each ball mill batch with optimum ball mill time are comparatively homogeneous. The Properly atomized and mechanically alloys containing large amount of transition element have a number of fine and dispersed oxides and intermetallics, and these alloys are expected to be high strength materials at high temperature resulting from the slow growth of grain and intermetallics composed of transition elements. The microstructures of atomizing and mechanical alloys and those annealed for 1hour from 300(573) to 500℃ (773k) were observed using X- ray diffraction and transmission electron microscopy. The phase decomposition of these alloys also was extensively investigated. The microstuctural variations of the these alloys are great with annealing but are much less severe than those of only atomized powder and extrudate due to increasing Al₂O₃ compositions.

벼 잡종초기세대에서 이삭줄기 대유관속 수와 이삭 특성의 분리양상

김광호,안종국,서경인 建國大學校附設農業資源開發硏究所 2001 農資源開發論集 Vol.23 No.-

The segregation modes and the selection efficiency of large vascular bundle(LBV) number and panicle characteristics were measured in three hybrid populations of rice. F_1 plants of the three crosses showed different direction and degree of dominance in vascular bundle number and panicle characteristics. The panicle neck diameter(ND), number of primary branches(PB) and LVB showed a typical normal distribution in F_2. When F_2 plants were divided into two groups up culm length of 90cm, the distribution of LVB number and panicle characteristics were not different between two populations. The selected and non-selected F_3 populations showed no difference in distribution of LVB number and panicle characteristics. However, F_3 populations grouped by culm length of 90cm showed different distributions in LVB and 100-grain weight among six characteristics observed. In F_2 populations, ND showed positive correlationship with PB, LVB number and grain number per panicle(GN). ND was positively correlated with PB, LVB number, GN and panicle length in selected and non-selected F_3 populations.

LCC를 이용한 공조 방식별 비교 연구

김종국(Joung-Kuk Kim),정광섭(Kwang-Seop Chung),김영일(Young Il Kim) 한국지열·수열에너지학회 2012 한국지열에너지학회논문집 Vol.8 No.3

The purpose of this study is to make an economic analysis(Life cycle cost) of selecting optimal air conditioning system for a research building which is 8 stories with a total floor area of 32,010㎡. Energy consumptions of three proposed air-conditioning systems(Alt-l,2,3) that reflect the government green-growth policy are calculated and compared. The results show that life cycle cost of Alt-3(Ventilation DX AHU+EHP) is less than Alt-1(EHP+ventilation DX AHU) by 5.1%, and Alt-2(Absorption chiller/heater+EHP) by 34.3%. Annual energy consumption of Alt-3 is less than Alt-l by 9.9%, and Alt-2 by 37.4%. Annual CO₂ emission of Alt-3 is less than Alt-l by 9.9%, and Alt-2 by 0.2%.

유방 엽상종양의 임상적 고찰

김희정(Hee Joung Kim),김태선(Tae-Seon Kim),강희준(Hee Joon Kang),조향정(Hang Joung Cho),박인애(In Ae Park),노동영(Dong-Young Noh),윤여규(Yeo-Kyu Youn),오승근(Seung Keun Oh),최국진(Kuk Jin Choe) 대한외과학회 2000 Annals of Surgical Treatment and Research Vol.58 No.3

반도체 Ash 공정용 PWM 제어 Plasma 발생방법

이정호(Joung-Ho Lee),최대규(Dae-Kyu Choi),최상돈(Sang-Don Choi),이병국(Byoung-Kuk Lee),원충연(Chung-Yuen Won),김수석(Soo-Seok Kim) 전력전자학회 2006 전력전자학술대회 논문집 Vol.- No.-

This dissertation discuses about a ferrite core plasma source using low operating frequency without sputtering problem by the stored electric field. Compared with the conventional RF power system with 13.56MHz switching frequency, the proposed plasma power system is only separated at 400kHz, so that it makes possible to use of low cost switching elements, PWM control and soft switching. Moreover, it could improve the coupling efficiency for plasma and antenna by using the ferrite core in order to transfer the energy of the load. This dissertation tried to analyze new plasma generation method for the plasma generation system by modeling the plasma load and grafting the concept of impedance matching in order to interpret it with the formula. This dissertation verified the ferrite core inductive coupling plasma source authorized for 400kHz of low frequency power by applying to the semi-conductor ash process thru the measurement of ash capacity and uniformed plasma distribution on the actual wafer.

벼 種子의 低溫 發芽性에 관한 연구

안종국,정일민,홍성현 建國大學校附設 農業資源開發硏究所 1998 農資源開發論集 Vol.20 No.-

This study was conducted to obtain some basic informations by screening Oryza sativa cultivars available for direct sowing. Germination and emergence rate in low temperature (15℃), 1,000 seed weight, proline content and SOD activity of seed were investigated in 12 cultivars of glutinous rice and 14 cultivars of nonglutinous rice. Significant difference in germination rate was not observed among the cultivars, and emergence rate, germination speed and emergence speed varied among the cultivars, 2~87%, 4~99%, 2~72% in range. Emergence rate, germination speed and emergence speed were high in Oryza sativa "Daeripchalbyeo", "Baegna", "Sangnambatbyeo", "Sinseonchalbyeo", "Jeogna" and "Inbujinado", and low in O. sativa "Jado", "Hyangrni", "Dasanbyeo" and "Heugmi". Many native varieties of Oryza japonica with glutinosity showed high values in emergence rate, germination speed and emergence speed. Average number of days for emergence became shorter, as emergence rate of a variety was high, and the varieties with high emergence coefficient tended to belong to Oryza japonica cultivars with glutinosity. Negative correlation was observed between proline content and germination rate at low temperature, and very high positive correlation was recognized between proline content and SOD activity.

靑溪山의 植生에 關한 硏究

宋政勳,延明訓,梁金喆,沈載國 中央大學校 基礎科學硏究所 2001 基礎科學硏究所 論文集 Vol.15 No.-

A study on the forest vegetation of Mt. Cheong-gye was conducted from March 2000 to Rugust 2001. By the physiognomy and the ZM method, the vegetation of the Mt. Cheong-gye was classified into six plant communities and two plantations ; Quercus acutissima, Quercus mongolica, Quercus aliena, Quercus variabilis, Pinus densiflora, Betula davurica community, and Larix leptolepis, Robina pseudo-acacia plantation. Q. mongolica community occupy the largest area. Oak plant communities whow high appearance frequency at mesic soil condition such as western side slope and saline. On the other hand P. densiflora community appears at xeric condition such as sidgeline of the mountain. Considering the frequency distribution of DBH-class in each plant community, this area is recognized as secondary forest and intermediate succesional phase after disturbance.

Age-hardening Characteristics of an Ag-Pd-Cu-Au Dental Casting Alloy

Hyo-Joung Seol(설효정),Gi-Chul Kim(김기철),Kuk-Hyeon Son(손국현),Hee-Kyung Lee(이희경),Yong Hoon Kwon(권용휸),Hyung-Il Kim(김형일) 대한치과재료학회 2004 대한치과기재학회 학술대회 Vol.2004 No.8

Comparison of Gas Chromatographic Method with Enzymatic Method for Cholesterol Determination in Milk and Cream

Dong-Kuk Lee,Joung-Jwa Ahn,Hae-Soo Kwak 한국식품과학회 1997 Food Science and Biotechnology Vol.6 No.4