흑연-메소페이스핏치 복합재료의 열이방성

유승곤,김영일,이보성,주혁종 忠南大學校 産業技術硏究所 1986 산업기술연구논문집 Vol.1 No.1

In the development of thermal anisotropic materials with natural graphite powder and pitches as raw materials, extruding and hot-press method were investigated. Pitches should be reformed to mesophase pitch precursor by thermal pretreatment for using as a binder, and the heating rate was recommended within 0.2℃/min in the carbonization process. The tensile strength of axial direction of all specimens was about three times larger than that of radial direction and it could be increased about 25-60% by adding 1% chopped carbon fiber. The thermal expansion coefficient of axial direction was about 1/3-1/5 than that of radial direction and the thermal expansion was repressed by adding carbon fiber. The thermal conductivity of carbon fiber added specimens was increased with increasing the temperature, while that of without carbon fiber was decreased. The thermal conductivity of axial direction was about 8.0-4.58 times larger than that of radial direction by adding carbon fiber in the range of 0-400℃. As a general, properties of hot-pressed specimens were better than those of extruded specimens.

植物體의 水溶性 成分의 抽出 메카니즘

유승곤,송봉준,이보성 충남대학교 공업교육연구소 1985 論文集 Vol.8 No.1

Water soluble components of Persicaria hydropiper have an insecticidal effect. The extraction mechanism of water solubles from Persicaria hydropiper was studied and it turned out to be a diffusion model. The diffusivity was logarithmically increased with respect to extraction temperature (20…70℃) showing the values in 0.7…2.65×10^-7 cm²/min. Some variables which have an effect on extracted quantity of water solubles were also observed. As a result, optimum operatin conditions and empirical equation were presented for the industrial scale extraction.

Attrition Reactor에서의 힘의 소모량 측정에 관한 연구

劉承坤 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.1

The milling effect of Attrition reactor was very successful using stainless steel balls as a milling media. But Attrition reactor need large amount of power consumption to agitat the heavy milling media. Power measurements were studied with a dynamometer which was attached to the torque table. Power consumptions were measured by changing agitation speeds, kinds of milling media, heights of milling media, positions of stirrer, stirrer types, and so on.

버들여뀌의 水溶性 成分의 殺충效果

송봉준,유승곤,이보성 충남대학교 공업교육연구소 1986 論文集 Vol.8 No.3

The water-soluble extract of Persicaria hydropiper was investigated with respect to its insecticidal effect. Small plant parasitic insects such as Aphis and Perichaeta communissma were wholly killed within 60 min, in the aqueous solution including 1250 ppm of the water-soluble extract. This extract was passed through cation and anion resins, and the non-adsorption parts were fractionated with membrane filters. The lower molecular fraction (MW/<500) exhibited a strong insecticidal effect and a new component having R_f value of 0.24 has been observed on the TLC from this low molecular fraction.

工業系 敎師의 再敎育을 위한 硏修 프로그램의 開發에 관한 硏究

李來然,劉承坤,羅聲雄,禹鎬吉 충남대학교 공업교육연구소 1983 論文集 Vol.6 No.2(A)

This study is intended to provide a more effective curriculum for the In- Service Training Program of industrial technical teachers. The curricula which have been used during last five years were carefully analyzed and the main conclusions are suggested as follows; 1) It must be given to the teachers to take optional subjects. 2) Experiments should be reinforced make up for the understanding of theory. 3) Practical studies and factory investigations have to be provided to the teachers during the In-Service Training Program. In case of needs, the expert engineer of industries become a instructor to the teachers for explaining the up-to-date industrial techniques and theories. 4) The teachers who attending the In- Service Training Program should take an active interest in the program for getting a remarkable results.

오존 처리된 페놀계 활성탄소섬유의 표면 특성

고경열,양범호,유승곤 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.3

액상에서의 오존 산화 반응에 의해 활성탄소섬유 표면 산소의 함량은 17.0wt%에서 22.4wt%로 증가하였고, 수소의 함량은 1.9wt%에서 2.7wt%로 증가하였다. 오존 산화 개시제를 달리하여 처리하면 활성탄소섬유에 생성되는 관능기들과 총산도 값을 조절할 수 있었다. 오존 처리되지 않은 활성탄소섬유의 총산도값은 0.631 meq./g인데 비하여, 1M NaOH 수용액을 개시제로 증가하였고, 특히 phenol그룹이 크게 증가하였다. NaOH로 처리하면 phenol그룹만 증가하였고, H_2O_2로 처리하면 phenol 그룹이 많이, carboxyl그룹이 약간 증가하였다. The oxygen and the hydrogen contents of activated carbon fibers increased from 17.0 wt% and 1.9 wt% to 22.4 wt% and 2.7 wt% by oxidation with ozone in liquid phase. The amount of functional groups and total acidity could be controlled with initiators of ozone decomposition reactions. The total acidity of ACF ozone treated ACF was 0.63 l meq./g, and particularly the phenolic group increased. The phenolic group only was developed when ACF was treated in NaOH solution, large amount of phenolic group and some carboxylic group only was developed when ACF was treated in NaOH solution, large amount of phenolic group and some carboxylic group were developed when ACF was treated in H_2O_2 solution.

Helicobacter pylori와 대장균의 Shuttle Vector 개발

조명제,이우곤,이상룡,김경희,안영숙,김성희,김현주,류복덕,최여정,윤영혜,백승철,전영석,이광호 경상대학교 유전공학연구소 1997 遺傳工學硏究所報 Vol.16 No.-

In this study, a vehicle vector using cryptic plasmids was constructed for gene transfer in Helicobacter pylori. pHP51(3.9 kb) and pHP489(1.2 kb) were selected for constructing vectors from cryptic plasmid of H. pylori isolates in Korea. The HindⅢ-digestedDNA fragment(1.2kb) of pHP489 and 1.6kb DNA fragment of pHP51 were ligated with a kanamycin resistance gene(aph3'-Ⅲ) from C. jejuni to produce the recombinant plasmids pHP489K and pHP51K, respectively. Transformation frequency of pHP51K by electroporation was low. But pHP489K could be effectively transformed into various H. pylori strains. In order to design an intermdiate vehicle vector for gene transfer into H. pylori, pBlueHP489K was prepared by recloning pHP489K DNA into pBluescript and pTZ19R vector. This vector permitted the DNA fragment containing pHP489 sequence, aph3'-Ⅲ, and cloned DNA to be cut and self-ligated in the SacⅠ site after cloning. ureA and ureB gene were inserted into pBlueHP489K, resulting in pBlueHP489K/AB. The DNA fragment containing pHP489, kanamycin resistance gene(aph3'-Ⅲ), and urease structural gene was cut away from pBlueHP489K/AB and self-ligated to generate pBlueHP489K/AB. pBlueHP489K/AB made urease-negative H. pylori strains restore their urease activity. By this experiment, pBlueHP489K was confirmed to be the vehicle system for transferring H. pylori genes.

Gelation에 의한 방사성 폐기물의 안정화/고형화 : Ca 및 Zr 첨가에 따른 이성분계의 열적 및 수화학적 안정성 Thermal/Hydrochemical Stability of a Binary System with Ca or Zr as an additive

김인태,박환서,유승곤,김환영,김준형 한국공업화학회 2004 응용화학 Vol.8 No.1

In the previous study, we suggested a new concept, named as GRSS(Gel-Route Stabilization/Solidification) and investigated a material system applicable to volatile radioactive waste, a reaction condition and chemical limitations. From these results, this paper investigated the effect of some additives, which have been considered as the major component of ceramic waste forms(apatite and sodium zirconium phosphate), on the thermal stability and chemical durability. The Si-P system with Ca at appropriate composition shows good thermal stability but low chemical durability while the Si-P system with Zr shows relatively low thermal stability but relatively high chemical durability.

人參成分 抽出에 관한 硏究

柳洲鉉,卞裕亮,劉承坤 연세대학교 산업기술연구소 1978 논문집 Vol.8 No.1

The amount of ethanol extract from ginseng was about 20.3% (w/w)and the yield of saponins from the extract was 5.5% (w/w). The optimum concentration of solvent was 60% ethanol. The optimum extraction time and temperature were respectively 2 hr and 80℃ when 0.5g of sample (Φ:0.25∼0.42mm) was added to 300ml of solvent. The empirical equation for the extraction of components was as follow: Y(θ,T,φ)=8log(Θ??100)-45log(T??×100)-60log(Φ??×100)+38 The partical size of sample had largely influence on the extraction yield, and the extraction mechanism was considered as diffusion.

겔화 반응 및 열처리한 금속염화물의 결정 및 구조특성

김인태,박환서,유승곤,김환영,김준형 한국공업화학회 2003 응용화학 Vol.7 No.2

A new concept for the stabilization and solidification of volatile radioactive wastes via gelation in a simple material system is introduced in this paper. Using sodium silicate as a reaction module and phosphoric acid as a catalyst or stabilization agent. CsCl is chemically converted to thermally stable compounds. The heat-treated product at 1000℃ contained a cristobalite crystalline framework and a glassy phosphorus-rich phase with a high Cs content. The morphology looked like honey flowing on the honeycomb. From TG/DT analysis, Cs could not be vaporized below 1300℃ by changing the aging conditions and molar ratio of Si/p. As a new concept, GRSS(gel-route stabilization and solidification) could give us the chance to make the high temperature waste conditioning process more stable and economical.