• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
• /
• pp.245-253
• /
• 2004

There has been recent demand for extending the life of age-degraded structures and equipment by such techniques as diagnosis, maintenance, safety assessment, and estimating residual life on iron-making plants and hydraulic, thermal, and nuclear power plants. These techniques take into account comprehensive scenarios that may cause malfunction and structural damage and allow an assessment of risk based on the likely scenarios. In particular the safety assessment and residual life estimation of age-degraded ships and equipment facilities require consideration of various factors such as mechanical and thermal stresses, corrosion, hardness, load variation due to changes of operating condition, crack generation and strength reduction of material by fatigue. In this study, a detail thermal stress analysis, one of useful techniques of safety assessment and maintenance, is performed on a blast furnace by using general FEM code (MSC/NASTRAN).

• 환경위생공학
• /
• 제21권2호
• /
• pp.1-10
• /
• 2006

Codonopsis pilosula and Adenophora triphylla were cultivated by sawing seeds, but the germination rate were low. To cultivate these two wild plants was very difficult. The marketable roots of the plants had low quality. The plant pathogens were very difficulty to prevent the diseases (Rhizoctonia, Pythium, Fusarium, Erwinia, Botrytis, Phythophthora) appeared in cultural state. For the extermination of the disease needs a lot of agricultural chemicals, the effect of remain behind an insecticides was high of a hazardous rate after harvest. On this studies, for the safe prevention of the diseases and the promote of seeds germination, we used Bacillus subtilis, B. liquefaciens, Paenibacillus polymixa, Pseudomonas putida separated in our research, these results would bring us harmless products of medicinal herbs for human.

• 한국안전학회지
• /
• 제12권4호
• /
• pp.86-92
• /
• 1997

Demand of LPG and LNG will increase continuously due to high calories, clearness, and convenience for usage. These gases are used widely for power plants, industrial plants, and domestic fuel. But accidents related with gas are increasing in proportion to increment of gas usage. Especially LPG has high ignitability due to weak dispersion to air and accumulation at low place because LPG is heavier than air. There are many hazards during transportation as well as production, storage, and usage of LPG. Commonly, tank lorry is used for inland transportation of LPG. If tank lorry were to raise leakage incidents and then LPG released during transporting, the accidents cause serious effects on the environment as well as human damage of surrounding area. In this study, therefore, hazards which cause LPG of tank lorry to leak during transportation were identified and risk of LPG transportation was assessed quantitatively. Also, the result of this study might be a useful measure for predicting damage and preparing safe transportation strategies of LPG tank lorry.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권5호
• /
• pp.609-616
• /
• 1998

Structural analyses are preformed for the high pressure steam turbine casings of the nuclear and the fossil power plants. An axisymmetric boundary element program for analysis of the casings is developed and applied in the process of practical structural design. To show the useful-ness and accuracy of the developed program results of the analysis are compared with those of the finite element analysis under hydrostatic test pressure, To check the validity of the axisymmetric numerical analysis of the casings the stresses resulting from the hydrostatic test pressure are measured using the strain gate. The results of the numerical analyses are compared and discussed with those of the experiments.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2005년도 연구개발 발표회 논문집
• /
• pp.813-818
• /
• 2005

Cooling seawater of thermal power plant which amounts about 5 cms per 100 MWe has hydro energy of about 3,000 kW at the thermal power plant complex, but this useful hydro energy has not been developed. Therefore, the feasibility study on hydro energy development of three power plants located in the southern and western coast of Korea was performed. Three target power plants are Samcheonpo, Boryeong and Hadong thermal power plant. The design head to discharge cooling water by gravity and the head caused by tidal level in the southwestern coastal area, could be used for the production of electric power. The various alternatives were studied and technical feasibility and economical efficiency were clearly proved.

• 한국환경농학회지
• /
• 제20권5호
• /
• pp.330-334
• /
• 2001

The polymorphism of Azospirillum isolates from ornamental rhizosphere and two reference strains were examined with respect to intrinsic antibiotic resistance (IAR) profile. All the isolates showed different intrinsic resistances to different antibiotics viz., tetracycline, kanamycin, nalidixic acid, streptomycin, ampicillin, spectinomycin and chloramphenicol. All the strains demonstrated susceptibility to high concentration of all antibiotics used in the present experiment. In addition to these general patterns, we also obseved the multiple antibiotic resistances of Azospirillum strains. The Azospirillum sp. OAD-11 was resistant to tetracycline, streptomycin and ampicillin, and Azospirillum sp. OAD-57 was resistant to tetracycline and streptomycin. Conversely, Azospirillum sp. OAD-9 possessed the dual susceptibility to tetracycline and spectinomycin, whereas Azospirillum sp. OAD-37 was dual susceptible to streptomycin and kanamycin. Such multiple antibiotic resistant/susceptible traits could be useful for the identification of the strains in field experiments or in molecular genetic transfer experiments.

• 생약학회지
• /
• 제29권3호
• /
• pp.149-154
• /
• 1998

Binding of urokinase-type plasminogen activator to its cellular receptor accelerate production of plasmin from plasminogen on the cell surface. Plasmin can digest extracellular matrix components and basement membranes through activating certain proMMPs, which is related to the invasiveness to the cells. Plasmin also acts the regulation of blood coagulation and relates closely to cardiovascular diseases such as stroke and coronary occlusion. Therefore, its inhibitors may be useful as antimetastatic agents and to the treatment of cardiovascular diseases. To search for plasmin inhibitors from plant resources, we screened plasmin inhibitory activities with 76 methanol extract of plant species. Among them, three plant samples showed strong inhibitory activities (>70%) and thirteen plant samples showed more than 50% inhibitory activities of plasmin. Their inhibitory activities were not directly related with uPA inhibitory activites and cell viability.

• 한국물환경학회지
• /
• 제23권1호
• /
• pp.1-11
• /
• 2007

The low nutrient environment in drinking water treatment plants and distribution systems cannot to be a good environment for bacterial growth. However, biofilms can be frequently found submerged surface in treatment plants and distribution system. Biofilms in distribution system are harmful, in that they can release organisms, and may cause problems in taste and odor of water. Control of these Biofilms is difficult, and disinfection alone is usually ineffective. Biofilms will not be eliminated from distribution systems by any contemporary technology available now or in the future. Therefore reduction of organic matter, improved disinfection, or a combination of these methods can be useful in controlling distribution system biofilms.

• 미생물학회지
• /
• 제35권2호
• /
• pp.169-172
• /
• 1999

한천 사면배지 대신 한지를 사용하여 시험관내 뿌리혹생성 실험방법을 개선하였다. 개선된 이 방법은 기존의 한천-시험관 법에 비해 전체 과정이 간단하며, 특히 굵고 단단한 유근을 갖는 콩과식물에서도 효과적으로 사용할 수 있다. 이 방법을 사용하여 Bradyrhizobium sp. CN9135을 접종한 차풀에서 접종후 7일째부터 조사된 식물개체의 6%에서 뿌리혹이 생기기 시작하여 14일 째에 조사된 모든 식물개체에서 뿌리혹이 생성되었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
• /
• pp.101-105
• /
• 2001

Due to their elastic anisotropy, ultrasonic testing of austenitic welds, frequently used in nuclear power plants, is much more difficult than that of isotropic elements. For accurate testing of austenitic welds, ultrasonic wave phenomena therein must be full understood. This study uses an accurate and effective numerical model, the mass-spring lattice model, for such phenomena. By comparing the numerical results with the corresponding analytical results, it is shown that the model is capable of accurately predicting the generation, reflection, refraction, and scattering phenomena of ultrasonic waves in anisotropic austenite welds. Therefore, the mass-spring lattice model will provide a very useful tool for simulating ultrasonic testing of austenitic welds, and thus will contribute to the enhancement of reliability of such ultrasonic testing.