Catalytic oxidation of hydrogen at nanocrystalline palladium surfaces

Oh, Chanick,Hong, Kwan Soo,Lee, SangGap,Park, Chung-hyun,Yu, Insuk IOP Pub 2006 Journal of physics, an Institute of Physics journa Vol.18 No.13

<P>We studied hydrogen adsorption onto the oxidized nano-palladium surface using <SUP>1</SUP>H NMR. In the α phase, the incoming hydrogen molecules dissociate and form OH<SUB>ad</SUB>. We confirm that the <img SRC='http://ej.iop.org/images/0953-8984/18/13/001/cm210477ieqn1.gif' ALIGN='MIDDLE' ALT='\mathrm {OH_{ad}} \rightarrow \mathrm {H_2O}(\uparrow) '/> transformation occurs during the α–β phase transition by observing a decrease in OH<SUB>ad</SUB> resonance intensity.</P>

오징어젓 숙성 중 N-nitrosamine 생성에 관한 연구

오창경,김수현,송대진,오명철,김성수 濟州大學校工科大學産業技術硏究所 1996 尖端技術硏究所論文集 Vol.7 No.1

본 연구는 오징어에 식염 20%를 첨가하는 고식염구와 식염 10%에 솔비톨, 에탄올, 젖산 등을 첨가한 저식염구로 나누어 오징어젓을 제조한 후, 이들을 숙성시키면서 N-nitrosamine의 생성 여부와 숙성 중 그의 전구물질인 아질산염과 질산염, DMA 및 TMA와 TMAO의 변화를 검토하였다. 오징어젓 숙성 중 pH는 저식염구가 5.79∼6.07, 고식염구가 6.05∼6.21 사이에서 변화하였다. 아질산염질소와 질산염질소는 각각 0.75∼1.04mg/kg 및 1.22∼1.42mg/kg 사이에서 변화하였다. TMA-N는 숙성 중 계속하여 증가하여 숙성 140일에는 고식염구가 20.1mg%, 저식염구가 14.9mg%였으며, TMAO-N는 생시료에서 27.9mg%이었던 것이 숙성 중기까지 완만하게 증가하다가 그 이후에는 다시 감소하였다. DMA-N는 숙성 중 계속하여 증가하였으며 숙성 140일에는 고식염구는 19.7mg/kr, 저식염구는 13.3mg/kg이었다. 오징어젓의 N-nitrosamine으로는 NDMA만이 검출되었고, 숙성 40일째에 저식염구에 흔적량, 고식염구에 3.8㎍/kg의 양으로 생성되었으며 숙성 중 계속해서 증가하여 57.5∼74.7㎍/kg에 이르렀다. Possibility of formation of carcinogenic N-nitrosamines and changes in their precursors during the fermentation of high salt-fermented squeid, Sepiell maindroni, group with 20% of salt and low salt-fermented squid group with 10% of salt, 6% of ethanol, 6% of sorbitol and 0.5% of lactic acid were investigated. pH during the fermentation of squid changed in the ranges of 5.79∼6.07 and 6.05∼6.21 in low and high salt group, respectively. The contents of nitrite- and nitrate-N during the fermentation were in the ranges 0.75∼1.04 and 1.22∼1.42mg/kg, respectively. Trimethylamine(TMA) was continuously increased during the fermentation and showed 20.1 and 14.9mg% in high and low salt group after 140 days of the fermentation, respectively, while trimethylamine oxide(TMAO) was gradually increased from the beginning until the middle period of fermentation and then was again decreased. Dimethylamine(DMA) was continuously increased during the fermentation and showed 19.7 and 13.3mg/kg in high and low salt group after 140 days of the fermentation, respectively. N-nitrosamines in salt-fermented squid was detected only N-nitrosodimethylamine(NDMA), which its amount was trace in low salt group and 3.8㎍/kg in high salt group on 40 days of the fermentation and then continuously increased in the ranges of 57.5∼74.7㎍/kg in both groups during the fermentation.

우리나라 主要經濟變數의 時系列分析

吳壽賢 淑明女子大學校 1975 論文集 Vol.15 No.-

Korean economy has been characterized by a fluctuation in its growth speed and in the last two decades the ratio of variables in the statistical figures has been greatly changed. The purpose of this paper is concerned with the investigation of cyclical movements to the Korean economy and restricted to consideration of twenty variables, by the use of time series analysis during the period of 1953-1974. this study translated Harvard Index into practical calculation of business cycles. The composite index number has been calculated by the use of residual method and involved the following steps: (1) To choose the fundamental data which have an effect upon the leading indicator in business cycles. (2) To get rid of smoothly the causes of irregular fluctuations by the use of three years moving average. (3) To compute the secular trend (linear) making use of least square method. (4) To calculate the individual index numbers and the composite index numbers. (5) To conclude by finding the period and amplitude of indicator in business cycles. This study is restricted to consideration of complete figureworke but the results show a tendency to the periodical fluctuations. It should be noted that much of this analysis might be described as qualitative evaluation. But this paper deals with the existence of busines cycle in the rate of change of the economic variables. Proper dynamic analysis has developed a totally distinct methodology. This paper have to come to a settlement finding a solution of leading indicator, coincidence indicator and lagging indicator between composite index numbers from now on. The following conclusions are reached through out the study: ① Economic variable tend to increase the possibility of business cycles during the last two decades and cyclical movements were also apparent. ② Business cycle of the major composite index numbers was in general a ten year cycle. ③ Final step consist in evaluation of the outstanding rate of change in the statistical fiqures, bringing about a change according to the economic growth. ④ This time analysis leaves behind a problem to distinguish between indicators of leading or lagging business cycles. But this is a hard nut to crack.

건톳 제조에 관한 연구

오명철,정창화,오창경,송대진,김수현 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.1

기관골 신생증 1예

오영상,이은우,정종혁,문승원,김수현,김동한,양혁승,박정환,박경옥,강성수,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Tracheobronchopathia osteoplastica is a rare disorder of unknown cause characterized by the projection of numerous bony or cartilaginous submucosal nodules into the tracheobronchial lumen with sparing of the posterior membranous portion of tracheobronchial tree. In the past, most of the cases were diagnosed as secondary finding at autopsy. Nowaday, the key component of the evaluation is flexible fiberoptic laryngoscopy and bronchoscopy, which typically demonstrates irregular spicules of subrnucosal bone and cartilage projecting into the tracheobronchial lumen and causing various degrees of airway obstruction. A 45 years old man was visited Sunchon St. Carollo hospital due to discomfort on throat. We saw several nodules just below vocal cord via laryngoscope. The computed tomography revealed multiple small calcified nqdules on trachea and both main bronchi. Pathologic finding of bronchoscopic biopsy showed abnormal proliferation of bony and cartilagious nodules in the tracheal submucosa. These fingdings were consistent with tracheobronchopathia osteoplastica. We report here on a case of tracheobronchopathia osteoplastica with review of literature.

감귤류 종자 추출물의 N-nitrosodimethylamine 생성억제에 관한 연구

오혁수,안용석,나임순,오명철,오창경,김수현 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.5

The effect of inhibition on N-nitrosodimethylamine (NDMA) formation by methanol extracts from 6 kinds of citrus seed (Citrus sunki, Citrus natsudaidai, Citrus suleata, Citrus tangerina, Citrus grandis and Citrus obovoidea) were investigated. The contents of moisture, crude protein, crude fat, carbohydrate, ash, flavonoid and totat phenol in citrus seeds were 4~6, l1~15, 32~46, 22~45, 2~4%, 12~24mg% and 53~133㎎%, respectively. The solid contents and yield of citrus seed extracts were 0.8~1.0 and 0.7~1.1%, respectively. Nitrite-scavenging activity by methanol extracts from citrus seeds increased with increasing extract dosage. Furthermore, the nitrite scavenging activity was pH dependent being the highest at pH 1.2 (42.7~96.9%) and the lowest at pH 6.0 (19.9~62.6%). Scavenging effects of nitrite by reaction time showed high effects under 3hr reaction time. The inhibition effect of NDMA formation by the citrus seed was strengthened as the amount of extract increased. The inhibition rate of methanol extracts from citrus seeds on NDMA formation showed 1.2~39.8%, 21.3~60.1% and 47.4~94.0%, according to add 1, 3 and 5㎖, respectively. Therefore, the inhibition effect of NDMA formation by the citrus seed was strengthened as the concentration of extract increased.

금연행위와 관련된 개인적 특성 및 경험과 인지 및 감정 사이의 상호관련성 분석

오현수 성인간호학회 2001 성인간호학회지 Vol.13 No.3

The Purpose of the study was to examine if individual characteristics and experiences related to smoking behavior identified from the literature were significantly associated with behavior-specific cognitions and affect in the same way as presented in Pender's Revised Health Promotion Model(Pender, 1996). The subjects selected for this study were 400 college students enrolled in more than 10 colleges located in Seoul and Kyunggi-Inchon province. According to the study results, personal factors (i.e.. perceived health status, the past history of disease, and symptoms related to smoking) and related behavior (i.e., the degree of alcohol consumption, and exercise) are significantly associated with behavior-specific cognitions and affect (i.e., perceived barriers to smoking cessation, perceived self-efficacy, and perceived benefits of smoking cessation). The canonical correlation between two groups of variables was .59. and it turned out to be statistically significant. Thirty-four percent of variance of the relationship between two group of variables was explained by two canonical variates which turned out to be significant in the study results. The result could be interpreted from the view of psycho-social area as follows : overall, this study includes important variables which explain the association between two groups of variables.

STWS를 이용한 최적추종 제어기 설계

吳顯哲,金潤相,安斗守 성균관대학교 1998 학술회의지원논문목록집 Vol.1998 No.-

This paper presents a design method of optimal tracking controller and reduced-order obsercer for time invariant comtinuous system using STWS(single term Walsh series). In optimal control, it is well known that the design problem with quadratic performance criteria often involves the determination of time varying feedback gain matrix by solving the matrix nonlinear Riccati equation and of command signal by solving the intergral equation, which makes design procedure quite difficult. Therefore, in order to resolve this problem this paper introduces STWS. In this paper, the time-varying feedback gains and command signals are determined by piecewise constant gains which can be easily determined by algebraic equation using STWS.

상악동구강 누관

현건수,권현오,양훈식,김중환 중앙대부설한국의과학연구소 1985 한국의과학 Vol.17 No.3

Laguerre 모델을 이용한 시스템 근사화

오현철,김윤상,안두수 成均館大學校 科學技術硏究所 1998 論文集 Vol.49 No.1

This paper presents an efficient method which can approximate unknow systems using Laguerre models. This method is to approximate system from only input-output information, which can exclude additional procedure for system description. and thus reduce the required computational burden. The proposed method has the advantage that an unknown system can be modelled without structural knowledge and assumption about the true model order and time delay.