폐 FRP/Urethane Foam 충진 혼성복합재의 제조 및 기계적 물성에 관한 연구

황택성,신경섭,박진원 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

욕조 생산시 발생하는 폐 FRP와 냉장고 등 가전품과 폐단열재로부터 발생하는 폐우레탄폼을 흡음 및 경량판재로 재활용하기 위하여 불포화 폴리에스테르 매트릭스 수지에 보강하여 복합재를 제조하였다. 또한 충진재의 함량의 변화가 복합재의 기계적 물성에 미치는 영향과 기지와 보강재간의 계면현상을 관찰하였다. 충진제의 함량이 70 wt%인 복합재의 인장강도는 82.34MPa로 가장 우수하였으며, 인장탄성율은 보강재의 함량이 증가함에 따라 감소하였다. 또한 굴곡강도와 굴곡탄성율은 폐FRP의 함량이 70wt% 충진된 복합재가 가장 우수하였으며, 그 값은 각각 72.5, 958.4MPa이었다. SEM 관찰 결과 70 wt% 충진된 충진제 매트릭스 수지의 계면에서 pull out 현상이 확인되지 않았으며 균열도 발생하지 않았고, 매트릭스 수지내에 충진된 폐 FRP/우레탄폼 충진제가 잘 분산되어 있음을 확인할 수 있었다. The waste FRP oocured in the fabrication of SMC (sheet molding campound) bathtubs and the waste polyurethane foam occured in electronic manufacture and waste insulator were applied as a soundproof and light weight pannel in the waste FRP unsaturated polyester matrix resin composites to recycle. The effect of filler contents of the mechanical properties and interfacial phenomena of the filler and matrix on the composites was evaluated. The tensile strength of composites reached its maximum value of 82.34 MPa when the filler content was 70 wt%, and the more content of reinforcement is increased, the more tensile modulus was decreased. The flexural strength and modulus of csomposites, reinforced 70 wt% with filler content, were dominant compared to the other samples to 72.5 Mpa, 958.4 MPa respectively. When composite of reinforced 70 wt% with filler content, it was confirmed that pull out phenomena and cracks did not occur in the interface of reinforcement and matrix resin through the SEM observation. Also, waste FRP and urethane foam were dispersed well into matrix resin as filler.

포괄수가지불제도 적용에 따른 산부인과 진료수입의 변화

황태연,유병철,정귀언,정수진,김성준,배기택,손혜숙,이종태,전진호,엄상화 인제대학교 2001 仁濟醫學 Vol.22 No.1

Objectives: Under the fee-for-service system, Korean hospitals have been suffering from the worsening profitability caused by law medical care fees. To overcome the difficulties, they have maximized the quantity of medical services and made relatively large investment in developing new medical services using high-priced medical equipment, medicines and medical supplies which were not covered by medical insurance system rather than reduced running costs. Materials and Methods: This study was made to analyze and forecast the revenue change of the department of Obstetrics and gynecology of an university hospital in Seoul, expecting the implementation of DRG system in 2000. Results: The results were as follows : 1.During the first two days of hospitalization. 41% of total medical service fee was occurred, which was thought that most of the check-ups and operations were made during this period. After two days of hospitalization, the new occurrence of medical service fee tended to reduce. 2.Out of total medical service fee, 67% of admission fee was occurred after 5 days of hospitalization. This was because medical service fees in obstetrics and gynecology department occurred during the first 5 days of hospitalization. 3.Out of fees for operation, treatment, medical supplies and blood transfusion. 71% was occurred during the first two days. 4. In case of fees for examination, 50% was occurred during the first two days. 5.A total of 53% of fees for medication and injection was occurred during the first 5 days. Conclusions: By the implementation of the DRG system, the income is forecast to increase by 800 won to 310,000 won by the disease group of obstetrics and gynecology department. To increase hospital income with the implementation of DRG system, the results of this study suggest that examinations should be done at out-patient departments before the hospitalization of patient, the discharge of patient should be noticed in advance to reduce the period of hospitalization, and admission appointment system should be implemented for the immediate operation and delivery.

폐타이어칩 보강 복합재의 제조와 결합재가 복합재의 기계적 물성에 미치는 영향

황택성,박진원 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

For the superior properties of mechanical and thermal aging, this investigation was carried out to develop the recycled of waste tire using various binders (Olefin, SBR Rubber, Polyurethane) for the reuse of the waste tire. In the experimental results show that the mechanical and the thermal aging properties of the composites decreased steadily with increasing content of the waste rubber. We obtained the excellent mechanical and thermal properties when the SBR which is a rubber adhesive was used. Because that total pore area was largen, interfacial adhesive force was weaken. And as the binder was dispersed in waste rubber, the mechanical and thermal aging properties were superior. This result was observed the same phenomena with morphologically.

폐 FRP/석분슬러지 충전 복합재의 제조 및 기계적 물성에 관한 연구

황택성,박진원,이철호 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

SMC 욕조 생산 시 발생하는 폐 FRP와 석재 가공공정에서 발생되는 석분슬러지를 재활용하기 위하여 불포화에스테르 매트릭스 수지에 분말 충전하여 복합재를 제조하였다. 또한 충전제와 매트릭스 간의 계면결합력을 향상시키기 의해 석분을 실란 커플링제 γ-methacryloxypropyltrime-thoxysilane (γ-MPS)로 전처리하여 복합재를 제조하고 기계적 물성 및 계면현상을 관찰하였다. 복합재의 굴곡탄성율은 석분함량이 10 wt%, 실란커플링제의 농도가 3 wt%일 때 가장 우수하였으며 석분 충전량이 증가함에 따라 감소하는 경향을 보였다. 또한 복합재의 초기 열분해온도는 352∼359 ℃이었으며 이 온도에서 중량감소율은 약 3%로 충전제의 양에 관계없이 거의 일정한 경향을 보였다. γ-MPS 처리에 따른 복합재의 물성변화를 관찰한 결과 충전제와 매트릭스 수지간 계면결합력인 증진되어 물리·화학적으로 안정한 결합을 이루고 있고 pull out현상이 발생하지 않음을 확인할 수 있었다 In order to recyle the FRP waste from SMC bathtubs and rock-crush sludge obtained as a byproduct of stones, the composite consisting of the FRP and rock-crush sludge and the unsaturated polyester matrix resin were prepared. To enhance the interfacial bonding force between the reinforcements and the matrix resin, the rock-crush sludge was treated with silane coupling agent, γ-methacryloxypropyltrimethoxysilane (γ-MPS ) and their mechanical properties and interface phenomena were examined. The flexural moduius of the composite containing 10 wt% rock-crush powder treated with 3 wt% silane coupling agent showed the maximum value. And also the initial thermal degradation temperature of composites were in the range of 352∼359℃. From these results, we observed that the weight loss of composites was almost constant regardless of the concentration of silane coupling agent. It is confirmed that the interface of the composites containing filler treated with γ-MPS was improved in that were were no pull-out phenomena between the reinforcement and matrix resin.

실내온도 5℃ 이하에서의 반품콘크리트 특성

진치섭,황택진,이승훈,김규학 부산대학교 도시문제연구소 2001 都市硏究報 Vol.11 No.-

To use concrete returned from job sites, a method to maintain the fresh properties of the returned concrete for a long time was studied by adding a retarder to stop cement hydration temporarily and adding an activator to the concrete to reuse next day in the same manner as an ordinary concrete.

굴착 단계를 고려한 쉴드 터널의 점소성 유한요소 해석

진치섭,황택진,서기영 부산대학교 생산기술연구소 2001 生産技術硏究所論文集 Vol.60 No.-

쉴드 터널공법은 연약지반이나 붕괴성 지반에 매우 유리한 터널공법이므로 날로 그 사용이 증대되고 있다. 그러나 이러한 쉴드 공법을 사용할 경우에는 대상 지반에 대한 충분한 지반 조사가 먼저 이루어져야만 한다. 본 연구에서는 쉴드 터널링을 모사 할 수 있는 점소성 유한요소를 통해 STAVIS라는 프로그램을 개발하였다. 이 프로그램은 Mohr-Coulomb 항복 규준을 사용하였고 지반의 변위 이력을 통한 유동계수 값을 사용하였다. 해석 대상은 부산 지하철 230공구로 하였고, 계측 라인에 대한 해석치와 계측치를 비교하였다. 융기 및 테일보이드 폐합단계, 라이닝 설치 후 지반 거동에 대한 해석결과가 계측치와 유사한 경향을 보여주었다. 본 논문의 연구결과는 지하 구조물의 가까운 곳에 쉴드 터널을 건설할 경우 유용하게 적용할 수 있을 것으로 본다. The construction method by the shield tunnel is increasing day by day, because it is useful method to soft ground and to be structure at neighboring place. Incase of use of the method, it must be planed enough a geological survey of soil and ground condition. Viscoplastic FEM program was developed STAVES in this study. The program is used Mohr-Coulomb yield criterion and adequate ·fluidity parameter was selected as comparing displacement histories of soil. The object of analysis was Busan Subway 230 site. The analytical values were compared with the measured values. The results of analysis are similar to the measured behavior of ground for heaving, tail void closure and liner installation. By using the results of this study, it can be applicable to construction of shield tunnel when it is nearly constructed to the underground structures.

Bleomycin이 Mouse신사구체 및 근위요세관 상피세포의 미세구조에 미치는 영향

김진택,황세진,정호삼,이규식 한양대학교 의과대학 1988 한양의대 학술지 Vol.8 No.2

Bleomycin, a glycopeptide antibiotic isolated from Streptomyces Verticillus, has been used as an anticancer drug active against human squamous cell carcinoma of skin and lung. It is well known that bleomycin inhibits DNA synthesis of tumor cell by scissoring DNA molecule and inhibiting DNA polymerase activity. Although bleomycin is very effective on various human cancers, it may damage certain normal cells to cause pulmonary and skin toxicity. In this experiment, the author pursued the effect of bleomycin on the mouse kidney, observing the ultrastructural changes in the proximal convoluted tubular epithelial cells and glomeruli. Healthy male mice(ICR strain) were used as experimental animals which were divided into two groups, the control and bleomycin treated groups. The bleomycin treated groups were subdivided into group of 3 times successive bleomycin treated and group of 7 times successive bleomycin treated. All experimental animals were given food and water ad libitum. The animals of bleomycin treated group were administered bleomycin 3 times and 7 times respectively, in a dose of 20 units per kg of body weight with 3 days interval. The experimental animals were sacrified in 24 hours after final administration of bleomycin. The specimens obtained from cortical region of left kidney were stained with uranyl acetate and lead citrate by the double contrast method and were observed with JEM 100cx-Ⅱ electron microscope. The results obtained were as follows: 1. In the epithelial cells of the proximal tubule the pinocytic vesicles were increased in number and also numerous autophagic vacuoles and the multivesicular bodies were found. 2. The deformed mitochondria and the dilated cisternae of rough endoplasmic reticulum were appeared in the epithelial cells of proximal renal tubule. 3. The basal infoldings were dilated and basement membrane were thickened and irregulary arranged at the basal portion of the epithelial cells of proximal tubule. 4. In the glomeruli the lamine densa of filterating membrane were irregulary arranged and thickened and many of the pedicles of podocytes were fusal together. It is consequently suggested that bleomycin damages both proximal convoluted tubular epithelial cells and glomeruli in mice kidney.

Starter 및 멸치액젓 첨가가 김치양념 및 겉절이 김치의 품질에 미치는 영향

최택권,박소희,유진현,임호수,조재선,황성연 한국식생활문화학회 2003 韓國食生活文化學會誌 Vol.18 No.2

양념에 Leu. mesenteroides, Lac plantarum의 젖산균과 멸치액젓 첨가가 김치 양념의 대장균군 제어, 속성촉진여부 및 관능적 특성에 미치는 영향을 조사하였다. Leu. mesenteroides과 젓갈을 첨가한 경우 초기 숙성이 촉진되나 후기 산패는 완만하였으며 Lac. plantarum의 첨가시에는 초기 숙성에는 큰 차이가 없고 후기 산패가 현저하게 진행되었다. 대장균군은 산도 0.80% 이상에서 사멸되었는데 leu. mesenteroides의 경우가 숙성이 촉진되어 보다 신속히 사멸시켰다. 총균수와 젖산균수는 초기에 starter 첨가구는 10^6CFU/mL 정도인데 반해서 starter를 첨가하지 않은 않은 처리구에서 총균수는 10^6CFU/mL , 젖산균수가 10^4CFU/mL 이었고 숙성 후에는 첨가균이 높은 수준을 유지하였다. 하지만 대체적으로 스타터의 첨가가 숙성 및 대장균에 크게 영향을 주지 못하는 경향으로 동일하게 나왔다. 관능적 특성에서는 Leu. mesenteroides 첨가구가 Lac. plantarum의 경우보다 우수하였다. 한편, 시판 겉절이 김치는 산도가 0.09~0.18%, ph 5.46~5.89, 총균수 2.2×10^6~3.1×10^7CFU/mL, 젖산균수는 2.1×10^4~6.6×10^5CFU/mL, 대장균수는 1.8×10^4~7.1×10^5CFU/mL, 염분 1.89%~2.51%으로 스타터 첨가 겉절이에 비해 ph와 염도를 제외한 품질 특성에서 전반적으로 낮은 값을 나타냈다. This study was performed in order to investigate the effect of Leuconostoc mesenteroides, Lactobacillus plantarum and salt fermented anchovy extracts on Kimchi sauce. The sauce was fermented more rapidly by addition of Leu. mesenteroids or salt fermented anchovy extracts on the early fermentation stage than the control, but it was fermented slowly on the late fermentation stage. When L. plantarum was added to the Kimchi on the early fermentation stage, the acidity of Kimchi didn't show a significant difference from the control, but acidity was remarkably increased on the late stage. Coliform group was disappeared when acidity of sauce was higher than 0.8% during fermentation. It was controlled by Leu. mesenteroides but not by L. plantarum. Total count and lactic acid bacterial count of the sauces with starter were 6.30×10^6~1.0×10^7 CFU/mL and 1.04~2.04×10^6 CFU/mL, respectively, but those of the control sauce were 10^6 CFU/mL and 10^4 CFU/mL, respectively. Those count of the sauce with starter were higher than those of the control sauce on the later stage of fermentation. Organoleptic quality of the sauce with Leu. mesenteroides was superior to that with L. plantarum.

콘크리트 크리프와 건조수축의 CEB-FIP Model Code와 ACI Code의 비교

전쌍순,박태균,황택균,엄장섭,진치섭 釜山大學校生産技術硏究所 2002 生産技術硏究所論文集 Vol.61 No.-

크리프 현상으로 인하여 구조물의 변형이나 처침은 시간의 경과와 더불어 중대하게 되고, 라멘, 아치 등과 같은 부정정 구조물에서는 건조수축으로 인한 부재의 변형 때문에 큰 수축응력이 일어난다. 따라서, 일시적으로 작용하는 하중에 비하여 지속하중이 큰 구조물에 있어서는 크리프의 영향을 설계해야 하고, 콘크리트 구조설계에서 건조수축은 매우 중요하다. 우리나라 콘크리트 설계기준을 비롯하여 세계각국의 코드에 크리프와 건조수축에 대해서 규정하고 있다. 그러나, 크리프와 건조수축에 관한 규정이 매우 복잡한 식으로 제시되어 있어 수 계산으로는 크리프 및 건조수축병형률을 계산하기가 어렵다. 본 연구에서는 Windows 환경에서 쉽게 CEB-FIP Model Code 및 ACI Code에 의한 크리프와 건조수축 변형률을 계산할 수 있는 프로그램을 작성하여 글 결과를 서로 비교 고찰하였다. Concrete under stress undergoes a gradual increase of strain with time because of creep deformations of the concrete. The final creep strain may be several times as large as the initial elastic strain. Generally creep has little effect on the strength of a structure, but it will cause a redistribution of stress in reinforced concrete members at the service loads. When concrete loses moisture by evaporation, it shrinks. Shrinkage strains are independent of the stress conditions in the concrete. If restrained, shrinkage strains can cause cracking of concrete and will generally cause the deflection of structural members to increase with time. In 2000, the Korea Concrete Institute Code took up CEB-FIP Model Code instead of ACI Code on creep and shrinkage of concrete, but their calculation procedures are tedious and difficult. In this study, programs are provided and it will be useful for the practicing engineers.

이동통신 멀티미디어 데이터서비스의 트래픽 특성 모델링 및 성능분석

정용주,백천현,김후곤,최택진,양원석,황흥석 한국경영과학회 2003 한국경영과학회지 Vol.28 No.2

The aim of this study is to identify the data traffic capacity of 3G mobile communication networks, especially of cdma2000-1X networks. Three-layered ON/OFF traffic model is used to describe the dynamics of data traffics and the process of data transmission such as packet scheduling. We construct a simulator fully incorporating packet handling process of cdma2000-1X data network as well as three-layered ON/OFF traffic model describing the behavior of source data traffics. To get influence of traffic parameters on performance measures, the extensive simulations were performed for several data sets which are obtained from real trace data or previous studies. The experimental results show that the engineered throughput satisfying QoS criteria is approximately 20% of total capacity. Finally, some proposals to improve the system capacity are followed.