Mg-Oxide에 담지된 알칼리 금속염 촉매상에서 메탄의 Oxidative Coupling 반응에 관한 연구

서호준 麗水水産大學校 産業技術硏究所 1995 産業基術硏究所 論文集 Vol.4 No.-

OCM(Oxidative Coupling of Methane) is discussed based on experimental observations in a fixed bed flow reactor at atmospheric condition and instrumental analyses such as FT-IR, SEM, etc. Among the alkali metal salts impregnated Mg-Oxide catalysts, the bialkali metal salts impregnated Mg-Oxide catalyst showed superior activity to monoalkali metal salts impregnated Mg-Oxide catalysts based on the C₂ yield. Activity order of alkali metal salts impregnated Mg-Oxide catalysts based on the C₂ yield was [LiCl+NaCl] 〉 LiCl 〉 NaCl 〉 KCl. This suggests bialkali metal salts to neutralize the acid site through the production of superbasicity due to synergic effect. Moreover, the production distribution of OCM over alkali metal salts impregnated Mg-Oxide catalysts shows that a competitive primary reaction of methane to C₂ or CO? has occured. Ethylene is proposed to secondary reaction of ethane.

불확실한 비선형 시스템에 대한 퍼지 관측기 설계

서호준,김동식 순천향대학교 부설 산업기술연구소 2001 순천향 산업기술연구소논문집 Vol.7 No.1

In the adaptive fuzzy sliding mode control, from a set of a fuzzy IF-THEN rules adaptive fuzzy sliding mode control whose parameters are adjusted on-line according to some adaption laws is constructed for the purpose of controlling the plant to track a desired trajectory. Most of the research works in nonlinear controller design using fuzzy systems consider the affine system with fixed grid-rule structure based on system state availability. The fixed grid-rule structure makes the order of the controller big unnecessarily, hence the on-line fuzzy rule structure and fuzzy observer based adaptive fuzzy sliding mode controller is proposed to solve system state availability problems. Therefor, adaptive laws of fuzzy parameters for state observer and fuzzy rule structure are established implying whole system stability in the sense of Lyapunov.

로듐(Rh)이 담지된 금속산화물 촉매상에서 합성가스 제조를 위한 이산화탄소 개질반응

서호준 여수대학교 2001 論文集 Vol.16 No.-

The effect of carrier in reforming of carbon dioxide to syngas over Rh(5wt%) promoted metal oxide(SiO_2, MgO, La_2O_3, TiO_2, Al-MCM-41)catalysts is discussed based on the experimental observations in a fixed bed flow reactor at atmospheric condition and SEM, XRD analysis. Catalyst activity depends on the carrier employed, and activity sequence of carrier promoted Rh(5wt%) after 8.6 hr is La_2O_3 > SiO_2 > MgO ≫Al-MCM-41 ?? TiO_2. The good activity of Rh(5wt%)/La_2O_3 catalyst seems to depend on the perovskite oxide, LaRhO_3(2 2 0 ; 3 1 0) or/and LaRh(1 3 1 ; 1 3 2) crystalline phases. Adding oxygen, 1.2 mlO_2/min to reactant contributes to eleminate carbon on Rh(5wt%)/La_2O_3 catalyst surface.

Ni/Ti0₂ 촉매상에서 CO₂ 개질 반응에 있어서 조촉매 및 Ni 담지량의 영향

서호준,유의연 全南大學校 觸媒硏究所 1996 觸媒硏究 論文集 Vol.18 No.-

The effect of Ni loading andition of promoters such as KCI, NaCl, CaO and MgO was studied on the CO₂reforming over Ni/TiO₂catalysts in a fixed bed flow reactor at atmospheric pressure. 10wt% Ni loaded catalyst showed optimum activity. The effect of promoters on the catalytic activity was Ca>Mg>K>Na in order. Adding promoter could be suggested that the reverse Boudouard reaction occur.

온실가스 저감을 위한 이산화탄소 개질반응에서 귀금속(Rh, Pd)을 담지한 금속산화물 촉매상에 침적된 탄소의 종류

서호준 國立 麗水大學校 환경문제硏究所 2001 環境硏究論文集 Vol.4 No.-

Carbon species deposited on noble metals(Rh(5), Pd(5)) supported metal oxide(La_(2)O_(3), Al_(2)O_(3)) catalyst in Carbon Dioxide Reforming(CDR) reaction were discussed based on the experimental observations in a fixed bed flow reactor at atmospheric condition and also on analysis results by SEM and FT-IR. The wisker type carbon was deposited on the Rh(5)/La_(2)O_(3) and Rh(5)/Ce(1)/Al_(2)O_(3) catalyst, but carbon nanotubes was produced on the Rh(5)/Al_(2)O_(3) catalyst. CDR reaction over Rh(5)/Al_(2)O_(3) and Pb(5)/Al_(2)O_(3) catalyst was suggested to be a method among the carbon nanotubes preparation method.

균일상과 불균일상에서 이산화탄소의 수소화반응

서호준 여수대학교 산업기술지역개발연구소 2000 産業基術硏究所 論文集 Vol.9 No.-

Hydrogenation of carbon dioxide by hydrogen was investigated on the basis of the product distribution of homogeneous and heterogeneous reaction in a fixed bed flow reactor. The main product of the both reaction was methane. The heterogeneous reaction using Pd(5wt%)Al□O□ catalyst was excellent, and produced methane of 82.03% yield at 800°C. However, the homogeneous reaction produced poor methane of 0.0046% yield at 800°C. XRD analysis showed that the active site of the catalyst was Pd(2 2 0) phase.

재료내 다중결함에 의한 SH형 초음파 산란장의 수치해석

이준현,이서일,조윤호 韓國非破壞檢査學會 1998 한국비파괴검사학회지 Vol.18 No.4

비파괴검사중의 하나인 초음파 탐상검사는 교량, 발전설비 및 석유화학플랜트 등의 각종 다양한 구조물들의 안전성 확보를 위한 내부결함 및 손상평가를 위하여 일반적으로 폭넓게 사용되고 있다. 초음파를 이용한 비파괴 평가 기술은 각종 구조물에 존재하는 내부결함에 의한 산란신호를 통해 건전성을 평가하는 기법이므로 결함의 신뢰성 높은 정량적 평가를 위해서는 결함으로부터의 초음파 산란신호특성에 대한 기본적 이해가 필수적이며 따라서 이를 위한 모델링 수치해석 연구가 요구된다. 본 연구에서는 동탄성 경계요소법을 이용하여 무한체내에 존재하는 다중기공 결함에 의한 초음파 수평횡파의 근거리 산란특성에 대하여 결함의 형상과 결함사이의 상호작용을 고려하여 해석하였다. 본 연구에서 얻어진 결과들은 결함검출 민감도의 개선 및 역변환 해석에 의한 정량적 비파괴 평가에 큰 도움을 줄 수 있다. In order to assure the reliability and integrity of structures such as bridges, power and petrochemical plants, nondestructive evaluation techniques are recently playing more important roles. Among the various kinds of nondestructive evaluation techniques, ultrasonic technique is one of the most widely used methods for nondestructive inspection of internal defects in structures. For the reliable quantitative evaluation of internal defects from the experimental ultrasonic signals, a numerical analysis of ultrasonic scattering field due to a defect distribution is absolutely required. In this paper, the SH-wave scattering by multi-cavity defects using elastodynamic boundary element method is studied. The effects of shape of defects on transmitted and reflected fields are considered. The interaction of multi-cavity defects in SH-wave scattering is also investigated. Numerical calculation by the boundary element method has been carried out to predict near field solution of scattered fields of ultrasonic SH-wave. The presented results would be useful to improve the sensitivity of flaw defection for inverse analysis and pursue quantitative nondestructive evaluation for inverse problem.

Formocresol pulpotomy와 연관된 함치성 낭종의 시험례

주태준,박호원,이주현,서현우 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

1904년 Buckley에 의해 치근관 살균제로 도입된 이후로 1:5로 희석된 formocresol을 사용한 치수절단술이 치아우식에 의한 유치의 비가역적 치수염시에 가장 많이 사용되어 왔다. Formocresol은 치수조직의 높은 고정능력으로 높은 임상적 성공률을 보이고 있으나 자체독성이 매우 강하여 영구 계승치 치배의 변위나 결손, 법랑질 형성 부전, 전신흡수로 인한 돌연변이 가능성과 암유발 가능성 역시 보고되고 있다. 또한 formocresol을 사용한 치수절단술 후에 과사용된 formocresol에 의한 만성적인 염증이 계승 영구치로 확산되어 퇴축법랑상피의 증식을 자극하고 법랑질로부터 퇴축법랑상피를 분리시켜 함치성 낭종을 형성할 수 있음이 보고되고 있다. 본 증례는 3년 전 응급으로 하악 좌측 제 2유구치의 formocresol을 사용한 치수절단술 후 정기 검진을 위해 내원한 환자의 방사선 사진에서 함치성 낭종이 발견되어 낭종 제거와 함께 유치의 발치를 시행했고 발치된 유치에서 formocresol cotton pellet이 제거되지 않은 채로 발견되어 formocresol이 장기간 남아있음으로 인해 낭종을 형성할 수 있음을 보고하는 바이다. Buckley's formocresol was first introduced as a pulp medicament in 1904, and since 1930, it has been the treatment of choice for primary molar pulpotomies. Formocresol has fixation effect of pulp tissue and high clinical success rate. But side effect such as displacement and loss of permanent successor, amelogenesis imperfecta, cyst formation, mutation by general absorption, possibility of cancer induction have been reported. Of those, dentigerous cyst can form in the periradicular region after formocresol pulpotomy caused by an alteration of the reduced enamel epithelium, which result in fluid accumulation between the epithelium and the tooth crown. The present case describes a 6-year-old girl who had accidentally discovered in the panoramic radiograph a single, well-defined, radioluscent area enclosing the second unerupted mandibular premolar. The second left primary molar had been pulpotomizied 3 year before. Surgical treatment was carried out, the primary molar was extracted and cystectomy was performed under local anesthesia. In the extracted second primary molar, formocresol cotton pellet was left in the pulp chamber. Histologic study confirmed the suspected diagnosis of dentigerous cyst. This report present a case of dentigerous cyst associated with inadequate formocresol pulpotomized deciduous molar.

위암 환자의 복강내 투여를 위한 Activated Charcoal-Alginate Bead 제형으로부터 Mitomycin C의 용출 거동

이진호,최선웅,서중기,김동민,정경수,오정연,김진향,노승무,민병무,김용백,김창식,박근성,강대영,송규상,양준묵,조준식,정현용,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Locoregional recurrence is the most common type of recurrence in surgical operation of gastric adenocarcinoma, and peritoneal dissemination is one of the most difficult problems in advanced gastric adenocarcinoma treatment. Because the peritoneal cavity is the most common site of the first recurrence after gastric cancer resection, intraperitoneal chemotherapy seems a logical choice for cancer chemotherapy. In this study, Mitomycin C (MMC)-activated charcoal (CH)-alginate (ALG) beads were prepared by the mixtures of CH particles adsorbed with MMC as an anti-cancer drug and aqueous alginate solution. The alginate is recognized as biodegradable, nontoxic, and biocompatible. The release of MMC from the beads in 0.1 M Tris buffer was stable and continuous until about 1 week. The MMC-CH-ALG beads can be applied in the peritoneal cavity for intraperitoneal chemotherapy since they provide a good adhesiveness on the tissue and controlled release pattern of the drugs.

도심지 이동통신 신호 예측을 위한 회절 경로의 선행추적

鄭白鎬,李鎬俊,李種瑞 호서대학교 공업기술연구소 2000 工業技術硏究所論文集 Vol.19 No.-

Predetermination of diffracted rays to predict signal propagation in urban mobile commumication environment is proposed. This technique shows significant improvement in CPU time compared with conventional ray tracing method, and can be applied to any complex propagation environment composed of arbitrarily shaped buildings and streets. The predictions of this method are in good agreement with the measurement made in Tokyo and Ottawa.