CTBN고무 분산 에폭시 복합재의 기계적물성 및 파단면에 관한 연구

洪錫杓,崔相久 全北大學校 1989 論文集 Vol.31 No.-

We examined the mechanical properties (flexural and impact) and fracture surface of CTBN(carboxyl terminated butadiene acrylonitrile) rubber dispersed epoxy composites which are cured with MTHPA(methyl tetrahydro phthalic anhydride) or DICY(dicyandiamide). Rubber dispersed epoxy composites are prepared to blend epoxy mixture with CTBN rubber or CTBN rubber modified epoxy. It contains 0-25% CTBN rubber of liquid compoment. The results obtained in this experiment are as follows ; 1. The flexural stength is better in using the CTBN rubber than CTBN rubber modified epoxy. 2. In excess of 25% CTBN rubber, the cured epoxy composites are closed to rubber rather than epoxy in properties. It is very flexible. 3. In respect of the flexural stength and flexural modulus, CTBN x13 rubber is superior to CTBN x8 rubber. In excess of 5% CTBN rubber, The mechanical properties of both decrease sharply. 4. In respect of the impact stength, flexural stength and rubber dispersion, MTHPA is superior to DICY.

카본블랙의 종류 및 배합제의 혼합방법에 따른 NR/HNBR 블렌드의 특성

洪錫勻,庾吉祥,金鍾石,崔相久 全北大學校 1992 論文集 Vol.34 No.-

It was studied how physical properties, heat resistance, oil resistance, ozone resistance of NR(natural rubber)/HNBR(hydrogenated acrylonitrile butadiene rubber) blends influenced by different mixing methods and various carbon black types. Of the various mixing methods, masterbatch mixing method was better than others in considering the overall stabilities of the compounds. The most important parameter which influenced on heat, oil and ozone resistance was rubber material than sorts of carbon black. The resistance for heat, oil and ozone of NR compounds were improved by blending HNBR and these effects were revealed clearly at elevated temperatures.

환경영향평가 실효성 향상을 위한 공탁제에 관한 연구

홍상표 청주대학교 산업과학연구소 2023 産業科學硏究 Vol.41 No.1

The Environmental Impact Assessment(EIA) has contributed to mitigating the negative effect of the adverse environmental impact of large-scale development projects. However, the reliability of the results of the EIA has been frequently controversial due to the insufficient investigation of the natural conditions for preparing Environmental Impact Statement(EIS). To restore EIA credibility, the Korean government has contrived the institutional establishment of the ‘EIA Depository System’. Various issues resulted from the insufficient environmental awareness of the project developers, and the boss-subordinate relationships between project developers and business agencies as subcontractor in EIS preparations was also studied. To reflect the appropriate expenses of EIS preparation subcontractors, and to compromise the conflicts of various stakeholders in EIA process,‘EIA Depository System’ can be applied to Korean EIA legislation system.

자기저항 동기전동기의 유한요소 모델링 및 정수 측정

홍정표,한성진,주수원 東亞大學校 附設 情報通信硏究所 1998 情報通信硏究所論文誌 Vol.6 No.1

The Synchronous reluctance motor is a sinewave ac motor and it has cylindrical surfaces on both sides of teh air gap. The stator is conventional polyphase ac stator, while the rotor has internal flux barriers shaped to maximize the ratio of d-axis to g-axis reactance. This paper presents the finite element analysis and parameter measurement of the synchronous reluctance motor(SRM). The model motor is a 3-phase SRM with the segmental rotor and its rating is 0.175kw. The torque characteristic is analysed by finite element method and compared with that from measurement.

0.412 MeV 감마선에 대한 원주형 NaI(Tl) 섬광체의 총 절대검출효율 계산

홍권표,신희성,이상윤,노성기 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.4

Total absolute detection efficiencies of a 7.62 cm(dia.) and 7.62 cm(height) cylindrical NaI(Tl) crystal have been calculated for 0.412 MeV r -rays from a source(point, circular disk, square and line type). In this calculation the linear energy-absorption coefficients based on Hubbell's data have been considered and then calculated total absolute detection efficiencies compared with those from Grosjean and Bossaert. Besides, the source axis-to-detector axis shift distance which, could give rise to about 0.05% deviation in the total absolute detection efficiencies has been calculated for a line-type source of 0.5 cm in its length when a source-to-detector distance is 5 cm. It is revealed that the total absolute detection efficiencies obtained in this study are considerably different from those of Grosjean and Bossaert. In addition it is found that the deviation induced due to an imperfect center of a line type source may be within 0.05% if the shifted discrepancy is no larger than 1.74mm.

수도권 매립지 粘土遮水膜의 透水特性에 관한 연구

洪相杓,金丁勖 서울大學校 環境大學院 1993 環境論叢 Vol.31 No.-

NATM 통신구터널 지보패턴에 관한 연구

홍원표,한중근,이상곤 중앙대학교 기술과학연구소 1998 기술과학연구소 논문집 Vol.28 No.-

우리나라에서 NATM 통신구터널에 적용되고 있는 암반분류형태 및 지보패턴은 지하철 도시터널과 같이 대형단면 터널에 적용되는 기준을 그대로 적용하고 있는 실정이다. 그러나 NATM 통신구터널은 대개 소형단면터널이며 깊은 tal도에서 시공되는 것이 일반적이다. 따라서 NATM 통신구터널의 설계 및 시공시에는 적절한 지반암반의 정량화 및 공학적 분류법을 별도로 마련하여 이 분류에 근거한 적합한 지보모델을 제시할 필요가 있다. 본 연구에서는 NATM 통신터널에 적합한 표준지보패턴과 암반분류모델을 7등급으로 구분 제시하며 제시된 암반 분류등급별 지보패턴에 대한 합리성이 터널시공사례에 대한 유한차분해석을 통해 검증된다. The classification of rock-mass and its reinforcement pattern used for Communication Cable Vault in Korea have been actually used such methods that applied to largesectional tunnel construction such as Subway urban-tunneling. However, in the case of small sized tunnel works for Communication Cable Vault which are generally adopted at deep depth, the proper reinforcing support model should be suggested on the basis of quantitative classification of rock-mass for design and construction. This paper presented standard reinforcement pattern and classification model of rock-mass for NATM of Communication Cable Vault. They are divided in to 7-categories of grades and reasonability of these suggestion is ascertained from numerical analysis for the construction of these suggestion is ascertained from numerical analysis for the construction of Tunnel.

粘性土地盤의 N値와 土質特性과의 相關性

홍원표,박성현 중앙대학교 기술과학연구소 2001 기술과학연구소 논문집 Vol.31 No.-

지반조사에서는 원위치시험으로는 표준관입시험, 정적콘관입시험, 동적콘관입시험, 스웨덴 식사운딩시험, 베인시험 등이 실시되고 있다. 특히, 이들 가운데 표준관입시험은 간편하면서도 유용한 원위치시험으로 가장 널리 이용되어져 오고 있다. 표준관입시험으로부터 얻어진 N치는 지반의 지지력, 침하량, 점착력, 내부마찰각, 상대밀도, 변형계수 등 다양한 해석정보를 얻는데 활용되고 있으나, N치의 지반특성과의 관계의 상관성에 대하여 아직 명확히 조사되어있지 않은 실정이다. 본 연구에서는 점성토지반에서의 표준관입시험에 의한 N치와 지반특성의 상관성을 규명하여 보고자 우리나라 서남해안지역의 연약한 점성토 및 내륙지역의 견고한 점성토에 대한 현장지반조사 및 실내시험 자료를 분석하였다. 본 연구의 결과는 결국, Atterberg한계, 자연함수비, 습윤 및 건조밀도, 일축압축강도와 압축지수 등과 같은 물리적, 역학적 특성의 예측에 이용될 수 있을 것이다. In soil investigations, in situ tests, such as standard penetration test, static cone penetration test, dutch cone penetration test, Swedish sounding test, vane test, etc, are performed as a part of main investigation. Especially, standard penetration test is most widely used as useful test in situ. N-value from the standard penetration test could give a numerous interpretation such as judgement of ground bearing capacity, settlements, cohesion, internal friction angle, relative density, modulus of deformation, etc. Nevertheless, in some respect to clear the correlations between N-value and soil properties are not enough yet. In this study, in order to find the correlations between N-value and soil properties in cohesive soils, the soil test data have been analyzed. The data was given by both the field soil investigation and laboratory test performed on soft clay in west and south coasts and stiff clay of inland areas in Korea. The results of this study might be available to predict some soil properties, such as the Atterberg limit, natural water content, wet and dry densities, unconfined compression strength and compression index, by use of the standard penetration test results in fields.

전치 태반의 임상적 고찰

홍관표,이성동,김왕수,정종일,장하종,정혁,한세준 朝鮮大學校 附設 醫學硏究所 1991 The Medical Journal of Chosun University Vol.16 No.1

This study was undertaken for the clinical evaluation and statistical analysis on the 38 cases of placenta previa who were admitted and treated from March 1, 1988 to Feb. 28, 1991. The results were as follows : 1. The incidence of placenta previa was one per 53 deliveries or 1.90% 2. There were 57.9 % total placenta previa, 21.1 % partial placenta previa, 13.1 % low-lying placenta previa and 7.9% marginal placenta previa. 3. Placenta previa has occured more often in multipara (63.2%) than primigravida 4. More than one-third (38.8%) cases of placenta previa had delayed admission until labor occured for some time following vaginal spotting has first time been noticed. More instructive prenatal education should be emphasized 5. Lower segment transverse section rate was 63.2%, classical cesarean section rate was 15.8% and cesarean hysterectomy was 9.8%. The rest of them were treated by vaginal deliveries of 5 cases(13.2%) 6. The perinatal loss associated with placenta previa was considered still higher : the premature death was 15.8% and term death was 2.6%. The problem of prevention of prematurity still remains to be studied. 7. There was no maternal mortality in our study

衛生埋立地의 Clay Liner 特性에 關한 硏究

홍상표 서울保健大學 1993 論文集 Vol.13 No.1

The purpose of this study is to analyze the specific characteristics of clay liner in Kimpo Metropolitan Landfill, such as chemical, physical, and hydrogeological factors, and then to predict the transit time of leachate constituents through clay liner. The results are epitomized as follows; 1. The transit time through clay liner can be predicted as 45∼10,711 years, provided that there are no molecular diffusion and sorption phenomena. 2. Soil characteristics such as clay and silt content, plasticity index, the content of particles> 2mm in diameter, soil pH, and the thickness of clay are satisfied with the criteria of clay liner in the sanitary landfill. 3. Soil characteristics such as hydraulic conductivity, hydraulic head of leachate, the slope of bottom, and the depth of groundwatertable are not to meet the requirements of clay liner in the sanitary landfill. 4. The sorption capacity would be sufficient enough to retard the migration of heavy metals, and to attenuate the concentration of biodegradable organic pollutants. 5. The hydraulic head of leachate caused by the flat slope of landfill bottom would be too high to prevent the migration of nonreactive species.