매쉬-심 용접 판재의 성형 한계

김형목,허영무,양대호,서대교 기계기술연구소 1999 성균관대학교 논문집 기계기술편 Vol.1 No.1

This paper describes experimental investigation on the forming limit for mash-seam welded sheets. The uniaxial tensile test was conducted to evaluate the mechanical properties of weld bead. Experimental forming limit diagrams were investigated for the different thicknesses and properties of welded sheets.

목모-시멘트판의 제조와 응용 연구(Ⅱ)

서정목,김형중 公州大學校工科大學生産技術硏究所 1998 論文集 Vol.6 No.-

Inexpensive and retrofittable insulation materials for existing home and buildings are urgently needed to provide the means of our nation's effort to conserve the energy. In this study our objectives were focused on collecting the data in setting up a manufacturing facilities and in evaluating the properties for the applications of wood-wool cement board. Wood wool from various kinds of wood sources was produced by using a designed wood wool making machine. Also, wood wool-cement boards were made by using various wood wools, cements, and additives. The properties of manufactured wood wool-cement board, such as fire resistance, specific gravity, thermal conductivity, acoustic insulation, and bending strength were evaluated. Considering the product cost and the insulation cost, we strongly believe that the wood wool cement board will be served as a retrofittable insulation materials successfully.

ZnO/ZSM-5상에서 저탄소가의 탄화수소로부터 방향족화의 성능향상

서교택,문세기,김형진 한양대학교 에너지 ·환경기술연구소 1995 에너지·環境技術論文集 Vol.2 No.-

n-헥산의 방향족화 반응에서 HZSM-5에 기계적으로 혼합 첨가된 ZnO의 영향을 연구하였다. n-헥산의 방향족화 반응에 있어서, HZSM-5 자체 만으로도 활성을 나타냄은 물론 HZSM-5에 ZnO가 첨가됨에 따라 활성이 더욱 증대되었다. 이는 ZnO/HZSM-5에서의 방향족화 반응은 이원 기능 과정임을 나타내는 것으로서, 이때 ZnO의 역활은 n-헥산의 탈 수소 반응을 촉진하는 것으로 생각된다. 첨가된 ZnO는 촉매의 산도, 결정성 및 표면적에는 거의 영향을 주지 못하는 반면, 전화율과 방향족 화합물로의 선택도와 같은 촉매 활성에는 많은 변화를 주었다. 그러나, 무엇보다도 중요한 것은 급격한 촉매 활성의 저하를 방지하는 것이라 할 수 있다. The effect of ZnO added to HZSM-5 catalyst by mechanical mixing in aromatization of n-hexane has been studied. It is shown that HZSM-5 alone is active for aromatization of n-hexane and the activity is enhanced by addition of ZnO to the HZSM-5 catalyst. This suggests that the aromatization on the Zno-added catalysts(ZnO/HZSM-5) is a bifunctional process, in which ZnO seems to catalyze the dehydrogenation of n-hexane. Addition of ZnO makes less change in acidity, crystallography and surface area, but leads to significant change in activity in terms of conversion and selectivity toward aromatics. What is more important, however, is that it prevents the rapid decay of catalyst-activity.

Swim-Stress에 의한 血漿 Corticosterone 增加와 腦 Monoamine 性 神經系의 關聯性에 대한 硏究

徐聖祚,金炯健,全普權 고려대학교 의과대학 1988 고려대 의대 잡지 Vol.25 No.1

There are many evidences suggesting that central, alpha-adrenergic but not beta-adrenergic or dopaminergic, pathways inhibit ACTH-corticosteroid secretion caused by various stimuli in a variety of animal species. But noradrenenergic activation has been reported to cause no change, inhibition, or stimulation of ACTH secretion. O'Conner and Chipkin reported that the response to warm swim-stress might involve central opioid pathway, whereas the response to cold swim-stress appeared not to be opioid mediated. In this paper, the influence of clonidine on the increase of plasma corticosterone level occurred by swim-stress at 4℃ or 20℃ was studied in male mice. The results obtained were summarized as follows: 1. The increase of plasma corticosterone (CS) occurred by swim-stress at 4℃ was not affected by clonidine, 500㎍/㎏, but the increase occurred by swim-stress at 20℃ (20-SS) was significantly inhibited by clonidine. 2. The increase of plasma CS occurred by 20-SS was not affected by prazosin, phenoxybenzamine, yohimbine. propranolol and haloperidol. But the inhibitory effect of clonidine on 20-SS induced increase of plasma CS was significantly antagonized by yohimbine and phenoxybenzamine but not affected by prazosin, propranolol, and haloperidol. 3. The increase of plasma CS occurred by 20-SS was significantly inhibited by reserpine, alpha-methyl-p-tyrosine, and p-chlorophenylalanine but not affected by iproniazid. And the inhibitory effect of clonidine on the increase of plasma CS occurred by 20-SS was not affected by ipronizid, reserpine, alpha-methyl-p-tyrosine, and p-chlorophenylalanine. 4. Clonidine increased plasma corticosterone level, and the increasing effect of clonidine was moderately enhanced by reserpine and alpha-methyl-p-tyrosine but not affected by the above adrenoceptor blockades. The results suggest that the increase of plasma corticosterone level occurred by 20-SS may be mediated by hypothalamic noradrenergic and serotonergic neurons and inhibited by clonidine via presynaptic α₂-adrenoceptor.

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%.

지렁이를 이용한 슬러지 안정화시 부하율의 영향 및 슬러지 종류별 안정화 가능성 검토

서성철,박종안,이노섭,배형석,이종화,허준무,김준현 순천향대학교 기초과학연구소 1997 순천향자연과학연구 논문집 Vol.3 No.2

Stabilization of organic sludges using earthworms was conducted in a laboratory to investigate the effect of feed rate on the vermistabilization, and feasibility of vermistabilization of various sludge was also carried out to further wider application of vermistabilization. Sludges used in this study were septic tank sludge, papermill sludge and brewery sludge. Sludge reduction, cast production, earthworm growth rate and cocoon production were monitored periodically to check degree of stabilization. Feed rate of septic tank sludge did not have a notable effect on the sludge reduction and cast production per unit weight or earthworm. There was also no difference in the earthworm growth rate per unit weight of the sludge removed among the different sludge feed rate. The amount of septic tank sludge, papermill sludge and brewery sludge per gram of earthworm per day were 0.06, 0.05, and 0.02g, respectively. The weight of increase of earthworm per unit weight of the sludge removed was 0.18g/g for the septic tank sludge, 0.21g/g for the papermill sludge, and only 0.06g/g for the brewery sludge. It was therefore concluded that brewery sludge was not suitable for vermistabilization mainly due to high organic content to be easily converted organic acid. The concentrations of several heavy metals, volatile solids, total organic carbon and total kjeldahl nitrogen in the cast were generally lower than those in the raw sludges.

전립선암과 전립선비대증 환자에서 혈청 유리 및 총전립선특이항원 측정의 의의

서혁준,박형민,권태균,정성광,김법완,이재태 경북대학교 의학연구소 2000 경북대학교병원의학연구소논문집 Vol.4 No.1

Purpose: This study was peformed to investigate whether the free to total PSA ratio(F/T PSA ratio) offers a better discriminant for the detection of patient with prostatic cancer(CaP) and those with benign prostatic hyperplasia(BPH) than serum total PSA alone. Materials and Methods: From September 1996 to February 1999, free and total PSA levels were measured on frozen sera samples of 154 men with BPH and 46 with CaP using immunoradiometric assay. Results: In all subjects, the mean total PSA was significantly higher in CaP group(72.57±66.58ng/ml) than BPH group(3.12±4.10ng/ml). The mean PSAD was significantly higher in CaP group(1.64± 1.86) than BPH group(0.08±0.01). The mean F/T PSA ratio was significantly lower in CaP group(0.19± 0.07) than BPH group(0.30±0.13). Among 41 subjects whose total PSA were between 4-20ng/ml, the mean PSAD was significantly higher in CaP group(0.37±7.16) than BPH group(0.17± 0.07), but the mean F/T PSA ratio was not significantly different between CaP(0.19± 0.10) and BPH group(0.25±7.13). By comparing the sensitivity and specificity of total PSA alone, PSAD and F/T PSA ratio on receiver operating characterislic (ROC) Cutie in all subiects and subiects with total PSA between 4-20ng/ml, F/T PSA ratio had no superiority than total PSA alone and PSAD for discrimination between CaP and BPH. Conclusions: We suggest that the F/T PSA ratio is not superior to total PSA alone and FSAD in the detection of prostatic cancer, and further evaluation of the usefulness of F/T PSA ratio should be required.

Angle씨 Ⅲ급 부정교합자의 Activator치료 전후 head posture변화에 관한 연구

서형식,차경석 대한치과교정학회 1994 대한치과교정학회지 Vol.24 No.2

This study was carried out to research the adaptation patterns of head posture after activator therapy in functional class Ⅲ malocclusion patents. For this purpose, 29 functional class Ⅲ malocclusion patients, from the ages of 8 to 13 years old, were used. 1. Increse in capacity of oral cavity capacity were found in all the samples, but craniocervical angulation were varied into incresed group and decreased group after therapy. 2. Head posture exhibited the compensatory adaptation in the relative growth increments of the vertical dimension, ALFH and PLFH. 1) A group with more PLFH and less sagittal angle showed relatively small growth increment in PLFH during the treatment period, thus craniocervical angulation was increased. 2) A group with less PLFH and more sagittal angle showed relatively great growth incrmenet in PLFH during the treatment period, thus craniocervical angulation was decreased.

공정관리 시방서 제정에 관한 소고

서형수 三陟大學校 1999 論文集 Vol.32 No.2

Now the world's economy is changing rapidly. GATT has been replaced by WTO since 1994, and multi-national trade agreement have broken the barrier of nations/ boundaries in economic sense. Thus all countries can participate in construction market wherever within WTO system. In spite of differences of race, language, custom, politics, economy, geography, weather, construction market become the object that each country in the world compete for. Therefore a lot of unpredictable troubles are expected in the future. Thus we need the circumstance where trouble among the nations can be reduced and construction industry can carry out its work smoothly. Thus the research is required in this regard. Process control specification and its smooth accomplishment is vital for success of project. Therefore in order to control construction task systematically and scientifically, process control specification is necessary.

망간산화물상에서 VOCs 촉매연소

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

This study has been investigated the pyrolysis effect of pretreatment gas on Mn-PC(Phthalocyanine) and Mn oxide catalysts for the combustion of methanol and acetaldehyde. TGA thermogram for Mn-PC showed about 88% loss of mass at 419℃. Also, the catalytic activity of the pyrolysed Mn-PC was compared with that of Mn oxides. The catalysts were characterised by performing thermogravimetric analysis(TGA) and X-ray diffraction(XRD) before and after they had been exposed in the presence of air or air and methanol mixture at 450℃. After pyrolysis of Mn-PC, Mn_(3)O_(4) in the presence of air at 450℃, there was a formation of new manganese oxide phase, Mn_(3)O_(4), Mn_(2)O_(3) confirmed by XRD, respectively. In the blank test of metahnol and acetaldehyde combustion, reactants conversion was not observed up to 440℃ and 320℃, respectively. The relative catalytic activity of Mn oxides on acetaldehyde combustion was summarized as following: MnO <MnO_(2) <Mn_(2)O_(3) <Mn_(3)O_(4). Catalytic activity of Mn_(3)O_(4) is better than of commercial catalysts (CK-306, CK-307) over 260℃.