표백에 의한 라디에타소나무의 청변 제거

김규혁,김형준,나종범,김재진 한국목재공학회 2003 목재공학 Vol.31 No.1

본 연구는 라디에타소나무 제재목의 균 변색을 제거하기 위한 표백처리의 사용 가능성을 조사하기 위하여 수행하였다. 염소계 표백제인 아염소산나트륨과 차아염소산나트륨은 표백조건(약제농도, 처리온도, 처리시간)의 조절에 따라 만족할만한 변색제거 효과를 얻을 수 있었다. 비염소계 표백제인 과산화수소는 표백조건의 조절만으로는 변색제거가 불가능하였으나 규산나트륨과 수산화나트륨을 활성제로 첨가하는 경우에는 염소계 표백제보다 탁월한 변색제거 효과를 나타내었다. 그러나 활성제 첨가에 따라 재색의 녹색화 문제가 발생하였는데, 앞으로 이러한 문제점을 해결하기 위한 연구가 진행되어야 할 것이다. 또한, 앞으로 본 연구를 통해 개발된 변색제거방법의 현장 적용을 후속 연구도 필요하다고 본다. The feasibility of using bleaching treatments for removing fungal stain was evaluated on heavily stained raiadta pine sapwood. Sodium chlorite and sodium hypochlorite appeared to destain fungal discoloration by providing proper treatment conditions (chemical concentration, treatment temperature, and treatment time), while hydrogen peroxide did not remove fungal stain under the bleaching regimes evaluated. The addition of sodium silicate and sodium hydroxide in the hydrogen peroxide solution as a buffer could remove fungal discoloration completely:; however, the color of wood surface turned faint green after bleaching, thereby reducing the lightness of bleached samples. The results suggest that hydrogen peroxide bleaching could be a feasible method for removing fungal discoloration of stained radiata pine sapwood, although further research is needed to solve the problem of color change after bleaching Also, further tests under field conditions are recommended.

Metallo-Pc 촉매에 의한 휘발성 유기화합물의 촉매산화

서성규,김상채,윤형선 여수대학교 1997 論文集 Vol.11 No.2

Catalytic oxidation of methanol as a volatile organic compound(VOC) was studied at atmospheric pressure in a fixed bed flow reactor system over metallo-Pc catalysts. The activity of these catalyst in terms of metal ion, pretreatment gas, reaction temperature, contact time was studied. The experiment was conducted at the reaction temperature of 200~350℃, CH₃OH in air of 2.29 mole%, the contact time of 0.31~3.73gㆍcat-hr/gㆍmol-feed. As a result of study, pretreatment with air and methanol mixture showed the best performance for catalytic activity. The increasing order of catalytic activites for methanol conversion to carbon dioxide and water was as follows : metal free-Pc < Zn-Pc < Fe-Pc < Cu(α)-Pc < Cu(β)-Pc < Co-Pc. The catalytic activity of Co-Pc catalyst was very good at low temperature. And, Co-Pc catalyst had many possibilities as an alternative catalyst for the expensive commercial oxidation catalyst.

VOC 연소에 대한 구리 프탈로시아닌의 촉매활성

서성규,윤형선 여수대학교 1998 論文集 Vol.12 No.2

The catalytic combustion of methanol as a model volatile organic compound has been investigated over copper phthalocyanine catalyst in a fixed bed flow reactor at atmospheric pressure. The catalytic activity for pretreatment effect was examined at reaction temperature: 200~380℃, methanol: 2.35mol% in air, contact time (W/F): 3.11g-cat.hr/g-mol. The pretreated copper phthalocyanine catalysts have been characterised by TG/DTA, XRD, FT-IR and EA analysis. The catalytic activity pretreated with air and Ch₃OH mixture, 450℃, 1hr was very excellent. Under this pretreatment condition, the change from copper phthalocyanine catalyst as organic metal to some new copper oxide was confirmed by various instrumental analysis. Also, the order of catalytic activity is summarized as follows: metal free-PC<Cu(α)-PC<Cu(β)-PC.

호흡성 분진중 석영분석시 FTIR-직접필터법의 현장적용 가능성 연구

김형준,피영규,노영만,김현욱 한국산업위생학회 2002 한국산업보건학회지 Vol.12 No.2

To study if the fourier transform infrared spectrophotometry(FTIR)-direct on filter(DOF) can be utilized for estimation quartz content in airborne respirable dusts from various manufacturing industries, analytical results were compared with those of the traditional KBr transfer (NIOSH 7602) methods. Respirable dust samples were collected using the 10mm Dorr-Oliver nylon cyclone equipped with a 25mm cassette. 30 area samples were collected from the stone, foundry, concrete and brickmaking factories. Quartz content was estimated using the intensity of the absorption peak of quartz at 799 cm_-1 by a FTIR. Respirable dust concentrations ranged from 0.25 to 1.25㎎/㎥, and were highest at the stone treating factory. Quartz contents quantified by the transfer method were higher than those of by DOF method for samples from the foundry, brick, and concrete factories. No statistically significant difference of quartz content in samples from the stone factory was found. The results of the study suggest that, although possible to use the FTIR-DOF method as a suitable substitute for analyzing quartz content, it is necessary to correct the influence of the interfering minerals in order to adopt the FTIR-DOF for routine analytical tool.

코발트 담지 카본블랙 촉매를 이용한 아세트알데히드 산화반응

서성규,윤형선 國立 麗水大學校 環境問題硏究所 2002 環境硏究論文集 Vol.5 No.-

This study was performed to investigate the possibility of acetaldehyde oxidation on Co/carbon black catalyst. The experiment was conducted at the reaction temperature of 200~440℃, the acetaldehyde concentration of 0.94mole% in air and the cobalt loading amounts of 2~60wt%. The characterization of the carbon black and Co/carbon black catalyst was carried out by TGA and XRD analysis. The thermal characteristics of the carbon black was stable to the high temperature(600℃). XRD result showed that Co/carbon black were destroyed and new metal oxide were formed such as Co_(3)O_(4). Co_(3)O_(4) crystallite addition on the catalysts surface provided the greatest enhancement of the catalytic activity. The order of activity on acetaldehyde oxidation was summarized as follow: SiO_(2)<TiO_(2)<carbon black<SiO_(2)-Al_(2)O_(3). It was found from the experimental results and the economic consideration that carbon black could effectively be utilized as a support for acetaldehyde oxidation. The activity of Co/carbon black catalyst were varied with the cobalt loading amount and the optimum loading content of cobalt was found 10wt%.

베이스 구조물 진동을 고려한 스테이지 입력성형기법 적용에 관한 연구

김형기,권오영,배규현,홍성욱 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

A base structure which mounts positioning stages is often subjected to vibration due to the reaction force against the stage motions. This paper deals with an input shaping method for positioning stage in consideration of vibration base structures along with the stage vibration. A dynamic model is established to investigate the vibration of positioning stage and base structure. Two input shapers, a conventional input shaper and a new input shaper, are applied to eliminate both the residual vibrations in base structure as well as positioning stage. Simulations show that the input shaping methods effectively remove the residual vibrations.

ZrO₂-CaO계의 침전생성상에 미치는 pH효과

이형복,정윤중,김진규 明知大學校 産業技術硏究所 1988 産業技術硏究所論文集 Vol.7 No.-

The crystal phase of 1000℃ calcined powder, which was coprecipitated from the mixed solution of ZrOCl₂-8H₂O and CaCl₂- 2H₂O was detected by the DTA, XRD and SEM. At that time the mixed solution was varied with ZrO₂/CaO mole ratio, i.e. ZrO₂/CaO=0.7/0.3, ZrO₂/CaO=1/1 and ZrO₂/CaO=0.3/0.7. And also the pH value was controlled with NH₄OH solution as 2,4,6,8,10 and 12, respectively. Each system had the behavior of the formation of monoclinic ZrO₂ with tile lower pH value. The former two system showed the formation orthorhombic CaZrO₃ when the pH was 10 and 12. But at the system ZrO₂/CaO=0.3/0.7, the little amount of cubic ZrO₂ crystal phase was detected to coexist with the orthorhombic CaZrO₃ at pH 12.

금속-프탈로시아닌 촉매의 물리.화학적 특성

서성규,윤형선 麗水大學校 産業基術硏究所 1999 産業基術硏究所 論文集 Vol.8 No.-

Physico-chemical properties of metal-phthalocyanines(PC) with several pretreatment conditions were characterized by TG/DTA, EA, UV-Vis, SEM and XRD analysis. Also, catalytic activities of metal-phthalocyanines with pretreatment conditions were examined by methanol combustion. The effect of pretreatment conditions on catalytic activity was discussed in this paper. The catalytic activity of metal-phthalocyanine pretreated with air and CH₃OH, mixture at 450℃ for 1hr was excellent. Under this pretreatment condition, the basic structures of Cu(α)-PC and Co-PC were destroyed, and formed a new metal oxides such as CuO and CO₃O₄, respectively. But Zn-PC was retained its basic structure in this pretreatment condition. The order of catalytic activity on methanol combustion was summarized as follow: Co-PC> Cu(α)-PC> Fe-PC> Zn-PC.

코발트 프탈로시아닌 촉매를 이용한 메탄올의 연소특성

서성규,윤형선 여수대학교 1998 論文集 Vol.13 No.2

The catalytic combustion of methanol as a model volatile organic compound has been investigated over metallo-phthalocyanine(PC) catalysts in a fixed bed flow reactor system at atmospheric pressure. The catalytic activity was examined with reaction temperature: 200∼350℃, methanol(CH3OH): 2.29∼2.35mole% in air, contact time(W/F):0.62∼3.11 g-cat·hr/g-mol. The order of catalytic activity is summarized as follows: metal free-PC<Zn-PC<Fe-PC<Cu(a)-PC<Co-PC. The pretreated cobalt phthalocyanine catalysts have been characterised by TG/DTA. EA and XRD analysis. The catalytic activity pretreated with air and methanol mixture, 450℃, 1hr was very excellent. Under this pretreatment condition, the change from cobalt phthalocyanine(Co-PC) catalyst to new cobalt metal oxide(Co3O4) was confirmed by EA and XRD analysis. This cobalt metal oxide has high catalytic activity on methanol combustion.

만성 신부전증 환자의 중중 고혈당에 따른 의식 변화 결정에 대한 연구

위형중,이창범,박성광,강성귀,임천규,박은주,윤경택,한상웅,안유헌,김호중· 대한신장학회 2000 대한신장학회잡지 Vol.19 No.6