Roll-Mill을 이용한 재생 발포스티렌과 고무 Blend의 기계적 물성

윤형구,박문수,허양일 全南大學校 觸媒硏究所 1998 觸媒硏究 論文集 Vol.20 No.-

In order to recyling expended polystyrene (EPS) wastes, volume-reduced EPS and rubber (NR, SBR) blends were prepared by melting-blending in a injection molder and investigated its mechanical properties such as impact strength and tensile strength. The volume-reduction process of EPS carried out by hot-pressed at 150℃ for 10 min using a roll-mill (called RPS) and compared with a hot-wind contacting method (TPS). Impact strength of RPS/rubber blend a increase of 2-5 times as compared with TPS/rubber blends. When the contents of rubber in RPS/SBR blends were around 15 wt%, maximum tensile modulus was obtained.

液體燃料 噴舞燃燒에 있어서 NO 生成擧動 硏究

鄭求海,許文會 忠州大學校 1988 한국교통대학교 논문집 Vol.22 No.-

Recently the power engines by combustion are rapidly increased. Accordingly environmental pollutant of exhaust gas from combustion does also increase rapidly. We know that there are NO??, SO??, Co, soot and others in the pollutant and it is strongly requested in society that the Behavior of these pollutant should be elucidated and their discharge should be decreased. For this it is important that the Behavior of environmental pollutants which is generated and become extinct in the burner of practical use should be elucidated. In this point of view I studied on the atomization of liquid fuel which is most utilized and the Behavior of Nox which generates most in that combustion.

혈관평활근세포에서 산화에너지대사 억제에 의한 아밀로이드전구단백질 대사의 변화

한문구,최웅,김헌식,안희열,한설희 대한치매학회 2002 Dementia and Neurocognitive Disorders Vol.1 No.1

Background: A reduction in the activity of cytochrome c oxidase(COX) has been recently identified in mitochondria from platelets and postmortem brain tissue of AD patients Sodium azide (NaN₃). a COX inhibitor, is an effective chemical agent producing energy shortage and oxidative stress both in vitro and in vivo system Furthermore it has been suggested that vascular compromise could be either directly involved AD pathogenesis or indirectly associated with triggering pathogenetic events leading to AD This study was performed to investigate amyloid precursor protein (APP) metabolism by inhibition of mitochondrial energy metabolism in cultured vascular smooth muslce cells (VSMCs) Materials and Methods: VSMCs isolated from the aorta of seven weeks old Spraque-Dawley rat were treated with NaN₃in a low concentration (100-500μM) or in a high concentration (1-100mM) Cellular proliferation and viability were determined by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenly)-2H-tetrazolium) assay Cellular APP was detected with N-terminal specific antibody 22C11. Celldeath was determined by observation of morphology and terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick end labeling stain (TUNEL) We used ginkgo biloba extract(EGb761) and melatonin as anti-oxidants to investigate the mechanism of latered APP metabolism Results: The viability of VSMCs was increased after treatment with 1 mM and 10mM NaN₃(p<0.05) unitl 3 hr and then dimnished Many TUNEL positive cells were found in 10mM and 100mM treatment group. but were not apoptotic in nature 22C11 immunoreactivity was not changed at 3 hr, 6hr, 12hr Anti-oxidants reduced cellular proliferation (p<0.05). but did not block TUNEL positivities and did not influence the 22C11 immunoreactivity In a low concentration NaN₃ treatment group the viability of VSMCs was increased concentration dependently(p<0.05) Immunoblot with 22C11 showed the concentration dependent decrease at 145 kDa, 125 kDa. and high molecular weight range (>160kDa) TUNEL staining showed DNA fragmentations and condensations of nuclear chromatin suggesting apoptosis After treatment with anti-oxidants, the cellular proliferation was more decreased (p<0.05), and TUNEL positive cell deaths were blocked Immunoreactivities of 125 kDa (immature APP). 145 kDa (mature APP). and higher molecular weight bands were recovered below 400μM of NaN₃ Immunoreactivity of 145 kDa was recovered in 100 μM NaN₃ treated group Conclusions: The presumed mechanism of low concentration COX inhibitor is the overproduction of reactive oxygen species resulting from a depression of the mitochondiral electron transport chain. whereas potential consequence of high concentration COX inhibitor might be related to decreassion of ATP synthesis and bioenergetic impairment Reactive oxygen radicals in response to low concentration COX inhibitor alter the processing of APP in VSMCs This investigation demonstrated analtered APP metabolism as a peripheral marker of AD Therefore VSMCs treated with low concentration COX inhibitor could be concsidered as a novel in vitro model of AD.

Al₂O₃ TiO₂ 담체종류별 Pt, PtRu 촉매의 산화특성

김문찬,신진실,이동구,최균 한국공업화학회 2005 응용화학 Vol.9 No.1

The volatile organic compounds (VOCs) have been recognized as major contributor to air pollution. The catalytic oxidation is one of the most important processes for VOCs destruction clue to getting high efficiency at low temperature. In this study, mono metallic Pt and bimetallic Pt-Ru were supported to TiO₂ and γ-Al₂O₃. In order to distribute metals uniformly, Xylene, toluene and MEK were used as reactants. The mono metallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XRD, XPS, TEM and BET analysis. As a result, Pt-Ru bimetallic catalysts were showed higher conversion than Pt mono metallic catalyst. Pt-Ru bimetallic catalyst was showed highest conversion on the γ-Al₂O₃support. In the VOCs oxidation, Pt-Ru bimetallic catalyst had multi point active sites, so it improved the range of Pt metal state. Therefore, bimetallic catalysts were higher conversion of VOCs than mono metallic ones.

고속 가변길이 디코더 설계

이문구,이강현 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.1

In this paper, Design on high speed VLD(Variable Length Decoder) using pipeline structure. Variable Length Decoder is received Nbit data from input block and decode signal via Shifting Buffer, Length Decoder and Symbol Decoder. The interior of shifting buffer in proposed Variable Length Decoder is filled input data then decoded with high speed using the pipeline structure, in here whose data is decoded in every clock.

위암 환자에서 위절제술후 나타나는 담도확장의 임상적 의의: 추적 CT 소견을 중심으로

윤구섭,백승연,이문규,김영환,오용호 울산대학교 의과대학 1993 울산의대학술지 Vol.2 No.1

A retrospective review of consecutive 35 patients'pre and post operative abdominal computed tomography was performed to determine frequency and degree of bile duct dilatation following Billroth Ⅱ operation for stomach cancer and it's clinical significance. Degree of intrahepatic biliary dilatation was classified as mild, moderate, marked according to the extension into central, middle and peripheral zone of liver, respectively. Three specialists on the abdominal image participated in analysis of those findings without prior information of the patients. Intrahepatic biliary dilatation was seen in 22 patients(63%) analysed by at least one radiologist, in 13 patients(37%) by at least two radiologists. Bile duct dilatation on CT was common finding and not necessarily meant tumor recurrence. Vagotomy and afferent loop resulted form Billroth Ⅱ were one of possible causes of bile duct dilatation. This study showed in the cases of bile duct dilatation without clinical and other radiological evidence of recurrence, no further study are needed and only enough to follow up study.

내측연수경색에서 관찰된 안구의 반대편 측방돌진

김지수,문소영,정선미,한문구,박성호 대한평형의학회 2003 Research in Vestibular Science Vol.2 No.2

고정자 자속벡타를 이용한 브러시리스 전동기의 전류제어 PWM

陳明哲,黃文龜 大田産業大學校 1993 한밭대학교 논문집 Vol.10 No.1

ABSTRACTIn this paper, a new PWM method and estimating means of field oriented stator cur- rent components for BLDC motor drive are presented. The field oriented stator current components is predicted by calculated stator flux from the stator voltage and current signals. The current control PWM using stator flux vector without rotor flux angle in- formation is also suggested. Performance of the proposed controller is observed through a simulation. In this paper, a new PWM method and estimating means of field oriented stator current components for BLDC motor drive are presented. The field oriented stator current components is predicted by calculated stator flux from the stator voltage and current signals. The current control PWM using stator flux vector without rotor flux angle information is also suggested. Performance of the proposed controller is observed through a simulation.

초등 교육 발전에 기여하는 교육대학의 현장지도 역할에 관한 연구

김성회 / 이종철 / 전구호 / 정용팔 / 최동준 / 문낙주 공주교육대학교 초등연구원 1977 公州敎大論叢 Vol.13 No.2

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이중혈류유발 심폐소생술이 심정지를 유발한 개의 단기 생존율에 미치는 영향

황성오,조준휘,강구현,김성환,문중범,이강현,이승환,윤정한,최경훈,홍은석 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background and Objectives: We previously reported that, compared with standard cardiopulmonary resuscitation(S-CPR), better hemodynamic effects could be achieved by simultaneous sterno-thoracic cardiopulmonary resuscitation(SST-CPR) in which we compressed the sternum and constricted the thorax circumferentially during the systolic period by using a device. This study was designed to assess whether SST-CPR, compared with S-CPR, improve the survival rate of dogs with cardiac arrest. Subjects and methods: Twenty-five mongrel dogs(19∼31㎏) were enrolled in this study. After four minutes of ventricular fibrillation induced by an AC current, animals were randomized to resuscitate with either S-CPR(n=13) or SST-CPR(n=12). Epinephrine(1 ㎎) was injected into the right atrium every three minutes after the beginning of CPR. Defibrillation was attempted after 6 minutes of CPR. Standard advanced cardiac life support was started if defibrillation was not successful. Results: SST-CPR resulted in significantly(p<0.001) higher systolic arterial pressure(91±47 vs 47±24 ㎜ Hg), diastolic pressure(43±24 vs 17±10 ㎜ Hg), coronary perfusion pressure(35±25 vs 13±9㎜ Hg), and end tidal CO2 tension(9±4 vs 3±2 ㎜ Hg). Two of 13 animals(15 %) resuscitated with S-CPR and six of 12 animals(50%) resuscitated with SST-CPR survived until 12 hours after cardiac arrest(p<0.05). Donclusion: SST-CPR, compared with S-CPR, improves the short-term survival rate in canine cardiac arrest.