• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.3
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• pp.226-233
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• 1997

예망어구의 유체역학적인 특성과 예망어구내에서의 유속 측정 자료를 기초로 어류의 측선 유수감각에 작용하는 유효한 유수자극량을 추산하고 정량화하기 위하여 예망어구내의 3차원적인 상대유속의 선형적인 분포정도를 모델링하였다. 예망어구내의 상대유속은 망지의 제반규격과 예망어구의 수중 전개형상에서의 각부 거리비에 따라 상대유속비를 선형적으로 수식화하여 본문의 식(3)과 (8)로 표현하였다. 이러한 상대유속비는 어류의 측선 유수감각기관에 의하여 탐지될 수 있는 와동 유수자극량의 지표로써 사용될 수 있다. 어류의 유수감각 예민도는 어류의 전장과 어체주위 상대유속에 의하여 선형적으로 변화되는 것으로 가정하고 본문의 식(9)와 같이 탐지가능한 상대유속차의 최소값으로 나타내었다. 예망어구내의 상대유속 분포에 관한 본 모델의 계산 결과는 실물예망어구에서 실측된 상대유속의 범위내에서 거의 근사하게 나타났으며 본 모델은 어류의 대망행동 모델링에서 예망어구의 유수자극과 어류의 유수감각 예민도를 상대적으로 정량화하여 어류행동의 반응요인으로 적용할 수 있을 것이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.295-296
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• 1999

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.311-320
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• 1998

The cryogenic fracture behaviors of austenitic stainless steel HN2 developed for nuclear fusion reactor were evaluated quantitatively by using the small punch(SP) test. The electrochemical polarization test was applied to study thermal aging degradation of HN2 steel. The X-ray diffraction(XRD) analysis was conducted to detect carbides and nitrides precipitated on the grain boundary of the heat treated HN2 steel. The mechanical properties of the HN2 steel significantly decreased with increasing time and temperature of heat treatment or with decreasing testing temperature. The integrated charge(Q) obtained from electrochemical polarization test showed a good correlation with the SP energy(ESP) obtained by means of SP tests. From the results observed in the x-ray diffraction and anodic polarization curve, it was known that the material the grain boundary. Combining SP test and electrochemical polarization test, it could be useful tools to non-destructively evaluate the cryogenic fracture behaviors and the aging degradation for cryogenic structural material.

• Corrosion Science and Technology
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• v.17 no.4
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• pp.183-192
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• 2018

Stainless steel can be classified into three categories depending on the microstructure as austenitic stainless steel, ferritic stainless steel and martensitic stainless steel. Generally, stainless steel is extremely resistant to corrosion as the name implies. However, under specific environments, susceptibility to localized corrosion such as pitting, intergranular corrosion and stress corrosion cracking increases. This paper reviewed the state of arts on intergranular corrosion mechanisms, countermeasures on intergranular corrosion and intergranular corrosion test methods. Intergranular corrosion is mostly related with chromium depletion at the grain boundary and sometimes with segregation of electroactive elements in solution annealed stainless steel. Countermeasures on intergranular corrosion include avoiding chromium depletion by heat treatment and the addition of alloying elements. Sensitization evaluation of stainless steel was performed either through acid immersion test or electrochemical test. The methods were standardized in (Japanese Industrial Standards). Even though are useful in evaluating the degree of sensitization for industrial purpose but do not provide detailed information about sensitization mechanism, cause and chromium profile.

• Korean Journal of Psychosomatic Medicine
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• v.8 no.1
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• pp.65-71
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• 2000

Objects : Aimed to test the hypothesis that neonatal testosterone exposure in female mice influences the development of testosterone-related pain inhibitory system and that testosterone administered in adulthood decreases the pain sensitivity. Methods : Thirty androgenized(testosterone propionate $100{\mu}g$ ip within 24 hrs after birth) adult female and twenty five control(normal saline $100{\mu}g$ ip within 24 hrs after birth) adult female mice were injected with testosterone propionate 1mg/kg/day for 3 consecutive days from 84th experimental days. Nociceptive sensitivity was measured before and after treatment of testosterone by tail flick latency on 84th and 86th experimental days. Results : 1) On the 84th experimental day, basal nociceptive sensitivity was significantly higher in the androgenized group($2.7{\pm}0.4$ sec) as compared to the control group($3.3{\pm}1.1$ sec). 2) Testosterone treatment on the 84th experimental day significantly lowered nociceptive sensitivity in both androgenized($5.2{\pm}0.9$ sec) and control groups($4.6{\pm}1.8$ sec). However the effect was significantly greater in the androgenized group. 3) Nociceptive sensitivity on 86th experimental day before administration of testosterone was significantly lower in the androgenized group($4.8{\pm}1.9$ sec) as compared to the control group($3.9{\pm}1.2$ sec). 4) Testosterone treatment on the 86th experimental day significantly lowered the nociceptive sensitivity in both groups, but the androgenized group($5.9{\pm}0.9$ sec) showed significantly lower post-treatment nociceptive sensitivity as compared to the control group($4.9{\pm}1.5$ sec). 5) Nociceptive sensitivity was decreased significantly after injection of testosterone once a day for two consecutive days in the androgenized group(${\Delta}2.1{\pm}1.0$ sec), but not in the control group(${\Delta}0.5{\pm}1.3$ sec). Conclusions : There may be a testosterone-related pain inhibitory system, the development of which is enhanced by exposure to testosterone in the neonatal period, and the activity of which is also mediated by testosterone in the later life.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.145-149
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• 1990

선택적 2광자공명 3광자 이온화과정을 Li와 Sr의 동위원소들에 적용시켰을 때, 공명준위의 AC Track 이동으로 인하여 분리효율과 이온화율은 레이저 파장과 세기에 예민한 함수가 됨을 보이고 동위원소분리의 최적 조건을 검토하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.92-92
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• 1997

• Journal of the Korean hospital association
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• v.21 no.5 s.194
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• pp.27-41
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• 1992

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.863-867
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• 2008

Pitch based activated carbon fiber(ACF) was prepared from reformed naphtha cracking bottom oil(NCB oil) by melt spinning. The fibers obtained were stabilized, carbonized, and then steam activated. The ACF was sensitized with Pd-Sn catalytic nuclei via a single-step activation approach. This sensitized ACF was used as precursors for obtaining copper plated ACFs via electroless plating. ACFs uniformly decorated with metal particles were obtained with reduced copper plating in the reaction solution. Effects of the amount of copper on characteristics of ACF/Cu catalysts were investigated through BET surface area, X-ray diffraction, scanning emission microscopy, and ICP. The amount of copper increased with plating time, but the surface area as well as the pore volume decreased. NO conversion increased with reaction temperature. NO conversion decreased with increasing the amount of copper, which is seemed to be due to the reduction of surface area as well as the dispersion of copper.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.05a
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• pp.101-101
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• 1999