• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2005.05a
• /
• pp.360-363
• /
• 2005

제주 Pilot Plant RO 처리수의 수질은 국내는 물론 외국의 하수처리장 방류수 재처리 사례와 비교하더라도 전혀 손색이 없을 뿐 아니라, 먹는 물로 사용하더라도 수질적으로 문제가 없을 정도로 깨끗하게 처리되고 있었다. 특히, 방류수 재이용에 가장 큰 걸림돌로 작용했던 과다한 염소이온과 염분농도 문제 가 완전히 해결됨으로써 농업 용수는 물론 조경 용수, 공업 용수, 지하수 인공함양 용수 등으로 재이용할 수 있는 좋은 대체수원으로 평가되고 있다. 방류수 재이용을 위한 재처리시설 투자를 위해서는 재처리수가 인체, 농작물, 지하수에 부정적 영향의 유무에 대한 심층적 연구와 경제성 분석에 친한 추가적인 연구가 이뤄져야할 것이다.

• Nuclear Engineering and Technology
• /
• v.27 no.4
• /
• pp.582-590
• /
• 1995

우리 나라에서 건설될 중저준위폐기물 처분장의 기본설계개념에 따르면, 중준위폐기물 동굴에는 점토질 뒷채움재가 설치될 예정이다. 이 뒷채움재의 후보물질로는 원료 입수의 용이성 및 경제성 측면에서 천연점토와 분쇄암석의 혼합물이 고려되고 있다. 그러나 이 혼합물이 폐기물처분장의 뒷채움재로 사용되기 위해서는 주요특성들이 뒷채움재의 요구사항을 만족시켜야한다. 이 보고서에서는 경상북도 연일지역에서 산출되는 천연점토와 분쇄암석 혼합물에 대해 핵종유출저지 관점에서 가장 중요한 특성인 수리특성과 방사성핵종 확산특성 및 역학적 특성을 측정하여 뒷채움재료로서의 사용 가능성을 평가하였다. 혼합물의 수리전도도는 동일 밀도에서 점토함량이 감소함에 따라 증가되었으나, 점토함량이 적은 경우에도 상당히 낮은 값을 유지하여 뒷채움재를 통한 핵종이동의 주요 메커니즘은 확산이 될 것이라는 것을 보여주었다. 압축점토에 대한 방사성핵종 복산계수 측정결과, 동일밀도의 나트륨벤토나이트에서 측정된 값의 범위 내에 있었으며, 점토-분쇄암석 혼합물의 액소성한계, 다짐특성, 압축강도및 압밀계수등의 역학적 특성도 나트륨벤토나이트-모래 혼합물에서 얻어진 값과 유사하였다. 이러한 결과들로부터 연일산 천연점토-분채암석 혼합물을 고가의 나트륨벤토나이트 대용으로 처분장 뒷채움재로 사용할 수 있다는 것을 알 수 있었다.

• Journal of Korean Society of Forest Science
• /
• v.78 no.4
• /
• pp.412-418
• /
• 1989

The stem segments of Ailanthus altissima were cultured on the Murashige & Skoog's medium(1962) supplemented with 0.1 mg/l BAP and 1.0 mg/l 2, 4-D for callus induction and proliferation, Shoot primordia were observed as greenish regions on the surface of yellow-brown calli about 8 weeks after culture. Shoot primordia were selected and transferred to the MS media containing various combination of BAP and 2, 4-D. Among these combinations the shoot primordia cell clusters on the medium added to 0.5mg/l BAP and 0.01mg/l 2, 4-D exhibited the highest number of shoot formation. These shoots were successfully transferred on the solid MS medium with no growth regulators for the rootings.

• Journal of Navigation and Port Research
• /
• v.28 no.10 s.96
• /
• pp.861-867
• /
• 2004

Generally, a silicone rubber and a chloride polyethylene(CPE) have been used as a binder for high-performance composite EM( Electromagnetic) wave absorbers. In this study, the EM wave absorption abilities for natural lacquer which is newly suggested as a binder were investigated MnZn ferrite composite EM wave absorbers mixed with the natural lacquer were prepared and their absorption ability was also investigated. The prepared MnZn ferrite composite EM wave absorbers mixed with natural lacquer showed an improved EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers mixed with the conventional binders. such as a silicone rubber and a chloride polyethylene(CPE). The matching frequency and the absorption ability of EM wave absorbers varied with the thickness of them.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.29-34
• /
• 2004

Generally, a silicone rubber and a chloride polyethylene(CPE) have been used for the development of high-performance composite EM(ElectroMagnetic) wave absorbers. In this study, the EM wave absorption abilities for natural lacquer which is newly suggested in this study as a binder for composite EM wave absorbers were investigated to develop an improved EM wave absorbers. In addition, MnZn ferrite composite EM wave absorbers mixed with the natural lacquer were prepared and their absorption ability was also investigated. MnZn ferrite composite EM wave absorbers which employs the natural lacquer as a binder showed an improved EM wave absorption characteristics in comparison with the conventional binder such as a silicone rubber and a chloride polyethylene(CPE). The matching frequency and the absorption ability of EM wave absorbers mixed with natural lacquer can be controled the change of the thickness of them.

• Composites Research
• /
• v.21 no.1
• /
• pp.30-39
• /
• 2008

In this paper, a parallel micro genetic algorithm was utilized in the optimal design of composite structures instead of a conventional genetic algorithm(SGA). Micro genetic algorithm searches the optimal design variables with only 5 individuals. The diversities from the nominal convergence and the re-initialization processes make micro genetic algorithm to find out the optimums with such a small population size. Two different composite structure optimization problems were proposed to confirm the efficiency of micro genetic algorithm compared with SGA. The results showed that micro genetic algorithm can get the solutions of the same level of SGA while reducing the calculation costs up to 70% of SGA. The composite laminated structure optimization under the load uncertainty was conducted using micro genetic algorithm. The result revealed that the design variables regarding the load uncertainty are less sensitive to load variation than that of fixed applied load. From the above-mentioned results, we confirmed micro genetic algorithm as a optimization method of composite structures is efficient.

• Archives of design research
• /
• v.17 no.2
• /
• pp.43-54
• /
• 2004

The appreciation of cultural properties related with what the aspects of society was is mandatory to understand our culture correctly. To make over all cultural properties to our descendants without breakage or damage is our natural duty and national obligation. On the contrary, inhabitants in the preserved area should be restricted and controlled by the cultural property law. The conflict between the inhabitants in the preserved area and the government raises economical problems and damages all the time. Especially it is time to discuss to mediate between them and solve the problems. This feasible study is a proposal to settle them up through renovating abolished school in the preserve area to the museum and a case to preserve the cultual properties as well as habitant's assets in that area.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.4
• /
• pp.606-614
• /
• 2006

The purpose of this study was to evaluate the polymerization contraction of composite resin(Tetric $ceram^{(R)}$, Ivoclar Vivadent Liechtenstein) according to various liners(Tetric $flow^{(R)}$, Ivoclar Vivadent, Liechtenstein/$Ionosit^{(R)}$, DMG, German/ $Vitrebond,^{TM}$ 3M-ESPE, USA). The strain gauge method was used for measurement of polymerization shrinkage strain. Specimens were divided by 8 groups according to curing units and liners. Group A, E: Tetric $ceram^{(R)}$ bulk filing, Group B, F: Tetric $flow^{(R)}$ lining, Tetric $ceram^{(R)}$ filling, Group C, G: $Ionosit^{(R)}$ lining, Tetric $ceram^{(R)}$ filling, Group D, H: $Vitrebond^{TM}$ lining, Tetric $ceram^{(R)}$ filling. Group A, B, C and D were cured using the conventional halogen light($XL3000^{TM}$ 3M ESPE, USA) for 40 seconds at $400mW/cm^2$. Group E, F G and H were cured using light emitted diode(LED) light(Elipar Freelight $2^{TM}$, 3M-ESPE, USA) for 15 seconds at 800 $mW/cm^2$. Strain gauge attached to each sample was connected to a strainmeter. Measurements were recorded at each second for the total of 750 seconds including the periods of light application. Obtained data were analyzed statistically using Repeated measures ANOVA and Tukey test. The results of this were as follows : 1. Contraction stresses in flowable resin and glass ionomer lining group were lower than that in compomer lining group(p<0.05). 2, Contraction stresses in LED curing light groups were higher than that in halogen curing light groups, but there was no significant difference (p>0.05).

• Journal of Korean Institute of Fire Science & Engineering
• /
• v.4 no.2
• /
• pp.1-9
• /
• 2008

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1995.10a
• /
• pp.715-719
• /
• 1995