Co/Mn/Br계 촉매상에서 p-자일렌 액상산화반응의 공정변수에 관한 연구

손용배,박경린,류태공,김정희,오인석,김영호,양현수 忠南大學校 産業技術硏究所 2001 산업기술연구논문집 Vol.16 No.2

Liquid phase oxidation of p-xylene using molecular oxygen has been carried out on the Co/Mn/Br-based catalyst system in acetic acid as a solvent. Process parameters(total pressure, partial pressure of oxygen and temperature) and kinetics of the reaction were studied as a basic study in the viewpoint for the development of new catalyst system and process. The total pressure above 20atm and the partial pressure of oxygen above 5atm were required to keep the reactant in the liquid phase and to overcome the mass transfer limitation of oxygen. The oxidation rate conversion were increased with increasing reaction temperature to the 100∼190℃ range. For a given initial concentration of p-xylene, the oxidation rate and the apparent activation energy were found to be of first-order and 4.24 ㎉/㏖, respectively. The effect of the third components added to the Co/Mn/Br catalyst was also studied. It was found that Ni is only a good additive that can promote the catalyst performance.

MPEG-21 표준의 구현을 위한 Testbed 구축

손정화,손현식,조영란,권혁민,김만배 강원대학교 정보통신연구소 2003 정보통신논문지 Vol.7 No.-

1990년대 후반부터 다양한 디지털 통신망을 이용하여 멀티미디어 컨텐츠 서비스가 가능하게 되었다. 하지만, 멀티미디어 컨텐츠의 전달 및 이용을 위한 기반 구조들의 독자적 발전 및 다양한 통합적 관리 체계 시스템으로 인해, 멀티미디어 컨텐츠 표현 방식의 호환성 문제, 혼재하는 네트워크 전달 방식과 단말 방식의 호환성 문제 등의 잠재적인 문제점이 발생한다. 이런 문제의 대안으로 현재 존재하는 기술 및 기반 구조들 사이의 연동을 통한 큰 프레임워크인 MPEG-21이 진행 중이다. 본 논문에서는 현재 표준화 작업이 진행 중인 MPEG-21을 기반으로 하는 Testbed를 제안한다. Testbed는 server, client, DIA(Digital Item Adaptation)의 세 모듈로 구성된다. Server의 역할은 멀티미디어 컨텐츠를 Digital Item(DI)으로 생성하고, client가 DI를 요구할 경우 DIA 모듈을 통해서 변환된 DI를 client에게 제공한다. DIA 모듈은 server에서 동작되며 client로부터 요청된 DI를 분석하고 client로부터 전송된 환경 정보를 이용하여 client 환경에 적합하게 변환된(adapted) DI를 생성하는 것이 주 기능이다. Client는 server에 저장되어 있는 DI를 선택하고 user preference, terminal capability 등의 필요한 정보를 server로 전송한다. Testbed에서는 스포츠 경기의 동영상, 정지 영상, 경기 내용, 역사를 기록한 파일 등의 DI를 이용한다. 표현 언어는 XML이며, HTTP 기반의 Web 환경에서 구동되도록 설계된다.

주택에서 Box Model을 이용한 평균 환기율 및 이산화질소 발생량 추정

배현주,양원호,손부순,김대원 한국환경과학회 2004 한국환경과학회지 Vol.13 No.7

Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate these factors by application of multiple measurements. For the total duration of 30 days, daily indoor and outdoor NO₂ concentrations were measured in 30 houses in Brisbane, Australia, and for 21 days in 40 houses in Seoul, Korea, respectively. Using a box model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the ventilation and source strength were estimated. In Brisbane, the penetration factors were 0.59±0.14 and they were unaffected by the presence of a gas range. During sampling period, geometric mean of natural ventilation was estimated to be 1.10±1.51 ACH, assuming a residential NO₂ decay rate of 0.8 hr^(-1) in Brisbane. In Seoul. natural ventilation was 1.15±1.73 ACH with residential NO₂ decay rate of 0.94 hr^(-1). Source strength of NO₂ in the houses with gas range (12.7±9.8 ppb/hr) were significantly higher than those in houses with an electric range (2.8±2.6 ppb/hr) in Brisbane. In Seoul, source strength in the houses with gas range were 16.8±8.2 ppb/hr. Conclusively, indoor air quality using box model by mass balance was effectively characterized.

DLTS에 의한 열처리시킨 HB-GaAs에서의 깊은준위

崔玄泰,金仁洙,孫貞植,裵仁鎬,金相基 嶺南大學校 基礎科學硏究所 1993 基礎科學硏究 Vol.13 No.-

Deep levels in horizontal Bridgman(HB) undoped GaAs were investigated by DLTS system personally manufactured. In as grown sample, three electron traps of which activation energies are T1(E?-0.32eV), T2(E?-0.54eV) and T3(E?-0.82eV) were observed. As sample was annealed at 650℃, T3 level was separated into T3?(E?-0.74eV) and T3 level. When sample was annealed at 800℃, only T3* level was observed. For sample annealed at 900℃, T3* and T3 level were observed. From these results, EL2's origin is very complicated complex and explanation is very difficult, but the model of As??-V??-A??-V?? is enough to explain the EL2's behavior of annealing temperature.

닭에서 오존수의 급여가 닭와포자충 감염에 미치는 영향

박배근,染谷梓,류시윤,김현수,조성환,전무형,손화영 충남대학교 수의과대학 동물의과학연구소 2001 動物醫科學硏究誌 Vol.9 No.-

Ozone is very effective in acute and chronic viral disease as a virucidal agent and in improving the general health of the animals. The effects of ozonized water supply against Cryptosporidium baileyi was studied in 2-day-old chicken. After oral inoculation of chicken with 1×10^6 oocysts, ozonized water(0.5ppm) and tap water were supplied to experimental and control group, respectively. The prepatent period of both group was 6 days postinoculation(PI). The patent period of experimental group was shorter(6-18 days) than that of control group(6-22 days). The number of oocysts in the feces were maximum on days 11 PI, indicating 1.99×10^6 oocysts/experimental chicken and 6.00×10^6 oocysts/control chicken. The number of discharged oocysts during experimental period was higher in control group than that of experimental group. In the view of febric bursa sections on 7 days PI, the number of endogenous development of C baileyi was smaller in experimental group that in control group. This results indicate that the autoinfected sporozoite were damaged by ozone. The ozonized water supply to chickens is alleviation cryptosporidiosis.

SBA-15에 담지된 전이 금속 촉매상에서 p-Xylene의 불균일 액상 산화반응

김영호,손용배,류재춘,양현수,전기원,박상언 한국공업화학회 2004 공업화학 Vol.15 No.1

화학적으로 개조된 SBA-15 실리카 위에 활성 전이 금속 종들(Co, Mn, Ni, Fe, or Cu)이 담지된 불균일 촉매를 제조하였다. 제도된 촉매상에서 p-xylene의 불균일 액상 산화반응이 손쉬운 촉매 분리를 위한 불균일 공정의 개발 가능성을 검토하기 위하여 수행되었다. SBA-15 위에 결합된 Co 종(Co-SBA-15)은 다른 전이 금속 종들보다 대응하는 방향족 카르복실산으로의 산화 반응에 가장 효과적인 것으로 나타냈다. 더 나아가 Co-SBA-15 촉매상에서 반응시간(0.5~9 h), 반응온도(130~190 ℃), 전압(10~25 atm) 및 산소 분압(1~9 atm)과 같은 반응 변수의 영향을 연구하였다. 높은 전환율에서 고체 생성물인 terephthalic acid의 형성은 매우 낮고 그때 활성점 위에서 고체 생성물의 쌓임으로 인해 촉매가 쉽게 비활성화 되었을지라도, p-toluic acid로는 고려할만한 선택성이 관찰되었다. p-Toluic acid 및 terephthalic acid를 향한 중간 산화 생성물들의 선택성을 기초로 추정된 반응 경로는 균일 Co/Mn 촉매 반응계에서와 비교하여 거의 같다. 이것은 Co-SBA-15 촉매가 균일 촉매적 행동을 하는 불균일 촉매이고 고체 생성물을 생성하지 않는 탄화수소들의 액상 산화반응을 위하여 잘 적용될 수 있을 것임을 시사한다. Active transition metal species (Co, Mn, Ni, Fe, or Cu) supported on a chemically modified SBA015 silica were prepared as heterogeneous catalysts. The heterogeneous liquid phase oxidation of p-xylene on the prepared catalysts was carried out to investigate the possibility of the development of heterogeneous process for easier catalyst separation.The Co species bound on the SBA-15(Co-SBA-15) was found to be the most effective for the oxidation to corresponding aromatic carboxylic acids than the other transition metal species. In addition, the effects of reaction variables such as reaction time(0.5∼9h), reaction temperature (130∼190℃), total pressure (10∼25 atm) and the partial pressure of oxygen (1-9 atm) were studied on the Co-SBA-15 catalyst. At high levels of conversion, the considerable catalytic activities to p-toluic acid were observed, even though formation of terephthalic acid, an solid product, was very low and then the catalyst was easily deactivated due to build--up of solid products on active sites. The proposed reaction network based on the selectivities of intermediate oxidation products for p-toluic and terephthalic acid was similar to that on the homogeneous Co-Mn catalytic reaction system. This indicates that the Co-SBA-15 catalyst is a heterogeneous catalyst which can behave like a homogeneous catalyst and may be well applied to the liquid phase oridation of hydrocarbons without formation of solid products.

키 프레임의 운동 유형에 기반한 2D/3D 동영상 입체 변환

박상훈,김만배,손현식 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

This paper presents a new method of converting 2-D video into 3-D stereoscopic video based upon the motion type of key frames. The proposed conversion method provides the stable display of 3-D stereoscopic depth. To realize this, we propose the concept of key frame that has the reliability of motion vector field(MVF) as well as the accuracy of estimated motion type. If a current frame does not belong to the key frame, its asscciated motion type follows the key frame. Therefore, the abrupt variation of the motion type can be avoided. As a result, the stereoscopic conversion can be smoothly varied between subsequent frames. Experimental results show that the stereoscopic conversion of any video can be shown in the stable manner.

돼지생식기호흡기 증후군(PRRS) 바이러스 감염시킨 돼지 기관의 병리학적 관찰

조성환,김현수,윤원기,전무형,류시윤,박배근,손화영,김무강 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

The porcine reproductive and respiratory syndrome virus was inoculated into swine tracheal organ culture. The ballooning degeneration of the tracheal ciliated epithelium and a decrease of ciliary activity from the tracheal organs infected with PRRS virus were observed one day post-infection(PI). Tracheal epithelium showed degeneration and focal necrosis 2 days PI. Epithelial necrosis and loss of cilia and epithelial cells became more severe 3 and 4 days PI. An entire loss of cilia and epithelial cells were recognized 4 days PI, however, control tracheal organs were normal during the period of the experiment except a little decrease of ciliary activities with time..

한국 재래 우 및 산양 위장관의 somatostatin cell에 대한 면역조직화학적 분포

조성환,김현수,박배근,윤원기,손화영 충남대학교 수의과대학 동물의과학연구소 1995 動物醫科學硏究誌 Vol.3 No.-

The relative frequency and distribution of somatoatatin immunoreactive cells were investigated by the immunohistochemical method in the gastrointestinal tract of the Korean native cattle and goat. The results obtained were as follows: In the Korean native cattle, somatoststin cells were a few in the pyloric and duodenal region and rarely seen in fundic region, jejunum, ileum, cecum, proximal colon, central coil, distal colon and rectum. In the Korean native goat, somatostatin cells were the most numerous in the pyloric region and the next in the fundic region. And they were a few in the duodenum, not detected in the cecum and sparse in the jejunum, ileum, proximal colon, central coil, distal colon and rectum.

제2형 당뇨병 동물모델인 OLETF 쥐에서 장기간 라미프릴 투여가 내당능 및 췌도 베타세포에 미치는 효과

고승현,윤건호,김명미,안유배,송기호,유순집,손현식,차봉연,이광우,손호영,강성구 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.25 No.6

연구배경:최근 소개된 HOPE(Heart Outcomes Prevention Evaluation)study의 결과에 의하면, 심혈관질환이나 이에 대한 위험인자가 1가지 이상인 9,541명을 대상으로 안지오텐신 전환효소 억제제의 일종인 라미프릴을 투여하여 사망율과 뇌졸증, 심부전, 당뇨병 합병증이 개선되었을 뿐 아니라 다른 항고혈압제에 비해 새롭게 당뇨병으로 진단되는 환자가 줄었음을 보고한바 있다. 이에 저자들은 라미프릴(ramipril)을 제2형 당뇨병 동물모델에 장기간 투여함으로써 당뇨병을 예방하거나 고혈당 상태 또는 인슐린 감수성을 개선시킬수 있는지를 알아보고자 하였다. 방법:생후 24주된 체중 400∼450g의 OLETF와 LETO 쥐를 대상으로 6개월간 라미프릴 경구투여 하였고 혈압, 24시간 단백뇨 및 인슐린 내성검사를 시행하였다. 6개월 이후로는 8주간 투여군과 대조군의 체중을 비슷하게 맞추어 내당능 상태를 평가하였고 이후 다시 8주간 고농도 포도당을 투여하였다. 경구당부하검사를 시행한 후 희생시켜 조직표본을 만들어 guinea pig anti­human insulin 항체로 염색후 DAB로 발색하여 point count 법으로 베타세포를 정량하였고, 면역염색으로 췌도의 변화와 섬유화의 정도를 관찰하였다. 결과:라미프릴을 6개월간 투여하였을 때 OLETF 쥐에서 1)체중 증가가 적었으며 2)경구 당부하검사시 포도당하 면적은 의미있게 감소하였고 3)인슐린 내성검사상 Kitt가 증가되는 경향을 보였으며 4)수축기, 이완기 혈압과 24시간 단백뇨양이 의미있게 감소하였고 5)체중을 맞추면 내당능 상태가 비슷해졌다가 고농도 포도당 주입시 다시 포도당하 면적이 대조군에서 더 증가되었다. 라미프릴 투여군에서 췌도변형 및 파괴와 탈과립, 췌도내 섬유화가 감소하였다. 결론:본 실험에서는 인슐린 비의존성 당뇨병 동물 모델인 OLETF 쥐에서 당뇨병 발생 이전 단계부터 장기간 라미프릴을 투여할 경우 체중증가가 적었고, 투여군과 대조군의 체중을 맞추었을 때는 내당능상태의 차이가 없아가 고혈당 투여시 다시 투여군과 대조군에서 의미있는 차이를 보였다. 라미프릴 투여가 베타세포의 기능면에서 이로운 효과를 보일 것으로 생각되었다. 따라서 비만한 환자에서 안지오텐신 전환효소 억제제의 장기투여는 단백뇨 감소, 혈압강하 효과 이외에 체중증가의 억제 및 당뇨병 발생을 억제할 가능성을 시사한다. Background : In a Heart Outcomes Prevention Evaluation HOPE study, ramipril, a long-acting angiotensin-converting enzyme (ACE) inhibitor, significantly reduced the death rates the number of myocardial infarctions, strokes, heart failure as well as the risk of complications related to diabetes and of diabetes itself. However, it is known that ACE inhibitors improve glucose tolerance or insulin sensitivity or reduce the incidence of diabetes. Methods : 24 week-old OLETF (Otsuka Long Evans Tokushima Fatty) rats weighing 400 ~ 450 g were used in this study. 4 groups of rats were examined in parallel for 40 weeks. The OLETF rats were randomized for treatment with an aqueous solution of ramipril (5 mg/Kg) daily [OL (RMP), n=10)] and with saline [OL (CON), n=10)]. The LETO rats were also randomized in the same was as the OLETF rats (LT(RMP), n=10, LT (CON), n=10). The blood glucose level, body weight, systolic and diastolic blood pressure was assessed every month. At 3 and 6 months, the 24hrs urinary protein concentration was measured, and as insulin tolerance test and oral glucose tolerance test were conducted in all experimental groups. After 6 months, the body·weight was matched for 2 months in each corresponding group. Subsequently, a 15% sucrose loading was done for 2 months. After the glucose tolerance test, the pancreas was excised and immuno histochemical staining was conducted for insulin to quantify the beta cell mass by a point-counting method. In addition, the islet morphology was evaluated in the pancreas. Results : Ramipril treatment for a period of 6 months improved the 2hr blood glucose level, the area under the glucose curve in the oral glucose tolerance test, insulin sensitivity in addition to lowering significantly systolic and diastolic blood pressure and 24hrs urinary protein level significantly in OLETF rats. Of note, a lower weight gain was observed in both the ramipril-treated animals at 6 months. After weight matching, the AUC g and 2hr blood glucose level values were similar between the corresponding groups, but a 15% sucrose loading worsened the AUC g value. Histologically, the islets were less disorganized and the extent of fibrosis was lower in the ramipril-treated OLETF rats in the trichrome stain. Conclusion : Long-term treatment of ramipril, a long acting angiotensin-converting enzyme inhibitor may be useful for suppressing weight gain and proteinuria in addition to having a protective effect on the islet to harmful stimuli such as hyperglycemia (J Kor Diabetes Asso 25:469~482, 2001).