산화 알루미늄 표면층의 전기적 및 전기화학적 성질

김정근,박정열 한국기술교육대학교 2004 論文集 Vol.10 No.2

Surfaces of bare aluminum, anodized aluminum in sulfuric acid and sealed anodized aluminum with hot water were teted by electrochemical impedance measurements at their open circuit potentials and by potentiodynamic anodic polarization measurements up to +500mV vs SCE from their open circuit potentials in 1M sodium sulfate solution to evaluate and understand the state of surface oxidation. The oxides were not detected by ordinary X-ray diffraction and they were found to be highly nonstoichiometric by Auger depth profile analysis. For the bare and anodized surfaces, the impedances were determined to be composed of resistance and capacitance of the barrier layer of oxide, while the impedance for sealed anodized surface was controled mainly by the very high impedance of the precipitated oxide in the porous layer of anodized oxide during sealing by the impedance measurements and analyses. Impedance of a surface increased with the increasing degree of oxidation of aluminum and this fact was well reflected on the anodic polarization curves. These impedance and polarization techniques have been complementary and successful in the evaluation. However, a point defect model for anodic passive film on aluminum was necessary to understand electrical and electrochemical properties of the film better.

전자기력을 이용한 연속용융도금

박정렬(Jeong-Real Park) 한국표면공학회 2000 한국표면공학회지 Vol.33 No.1

오스테나이트 스테인리스 강의 펄스 직류 플라즈마 질화처리층 조직 및 성분

박정렬(Jeong-Real Park),국정환(Jeong-Han Kook) 한국진공학회(ASCT) 1996 Applied Science and Convergence Technology Vol.5 No.4

오스테나이트 스테인리스강 304L을 고질소 저압 분위기에서 400~600℃ 범위내의 온도변수 50℃ 간 격차이에 따라 펄스 직류 플라즈마를 발생시켜 펄스작용 시간비에 따라 5시간씩 질화처리를 실시하였다. 처리 온도 500℃를 전후하여 질화처리층의 상과 조직이 현저히 다르게 형성되었다. 500℃미만 범위에서 저온일수록 펄스작용 시간비가 높을 때 질화층은 일종의 비화학량론적인 질화 스테인리스강으로 형성되었고 박피막을 이루며 균열이 많이 발생했다. 처리온도가 500℃보다 높을 때는 온도가 높아지거나 펄스작용 시간비가 50 s/100 s로 높아짐에 따라 질화층은 CrN 및 Fe4N 위주로 구성되어 주상정 조직을 이루며 균일하게 성장하며 무균열층이 된다. 500℃에서는 저온 조직 및 상과 고온 조직 및 상이 혼합된 질화층이 형성되며 취성에 대단히 크다. Austenitic stainless steel type 304L has been nitrided under the low pressure of high nitrogen environment for 5 hours by the square-wave-pulsed-d.c. plasma as a function of temperature 400~600℃ and of pulsation. At the temperature range lower than 500℃ and at the relatively high ratio of pulse duration to pulse period, nonstoichiometric stainless steel nitride has been developed in the form of a thin layer which has many cracks. At the temperature range higher than 500℃, with the increasing temperature or with the increasing ratio of the pulse duration to pulse period up to 50 s/100 s, the nitrided layer was composed mainly of CrN and Fe4N phases and became thick, uniform, columnar and nearly crack-free. The nitrided layer at 500℃ was mixed with the low-temperature layer and the high-temperature layer and was very brittle.

연구논문 - 철강재료 - : 크롬 도금층의 초경화처리

박정렬(Jeong Real Park),김영섭(Young Sub Kim) 대한금속재료학회(구 대한금속학회) 1996 재료.물성 심포지엄 Vol.- No.-

유기피복강의 습식 부식거동과 임피던스 특성

박익민,박정열,송연균,박세철 대한금속재료학회(대한금속학회) 1993 대한금속·재료학회지 Vol.31 No.11

Specimens of carbon steel coated with chlorinated rubber primer have been immersed in 5% and 0.05% NaCl solutions and in a 0.35% (NH₄)₂SO₄+0.05% NaCl solution. Their electrochemical impedances at their corrosion potentials have been measured as a function of immersion time. Measured impedance data have been analyzed according to an equivalent circuit representing impedances across the organic film and the interface between the film and substrate. The film and substrate have been deteriorated more at the higher salt concentration. The corrosion at the interface has been controlled by the anodic dissolution of steel substrate and accelerated with time.

냉장보관된 농축 먹이생물의 지방산 조성 변화와 농축먹이로 사육한 굴 유생의 생존율

임현정(Hyun Jeong Lim),박승렬(Sung Real Park) 한국수산과학회 1998 한국수산과학회지 Vol.31 No.4

cold storage of concentrated food phytoplanktons is a useful technique in supplying food organisms for artificial shellfish seed. One month after preservation at 4℃, we have measnred survival rate of the concentrated food phytoplanktons, Pavlova lutheri, Isochrysis galbana, Isochrysis aff. galbana and Chaetoceros calcitrans. Thereafter we determined survival rate of oyster larvae fed fresh and concentrated diets and fatty acid compositions of the fresh and concentrated food phytoplanktons. Survival rate of concentrated planktons ranged from 23% to 31% after one month at 4℃. The survival rate of oyster larvae fad cold shred food appeared generally higher than those fed fresh harvested food. Especially, the highest survival rate were found in the larbae fed cold stored concentrated I. aff. galbana. EPA and DHA increased after cold storage and the highest level of DHA was detected in I. aff. galbana. As DHA can role as an important factor in determing nutritional value, it would be better to use concentrated I. aff. galbana kept in cold refrigerator for oyster seed production.

무도장 내후성강의 장기 내식성 및 그 현장즉시측정법

박정렬,김규영,Park, Jeong Real,Kim, Kyoo Young 한국강구조학회 2004 韓國鋼構造學會 論文集 Vol.16 No.4

옥외 강구조물의 중요 소재인 무도장 내후성강의 장기 내식성을 평가하기 위해 우선 9년 이상 산업대기와 전원대기에 폭로된 본 강판 및 비교재 일반강판 시편의 천향면에 대해 중성의 인공우수에 침적시켜 전기화학적 부식전위, 임피던스 및 동전위 양분극 곡선으로 측정 및 그 결과를 고찰하였다. 산업대기 및 전원대기에 천향면으로 폭로된 내후성강 표면에는 부동태적인 안정화 녹층이 발달하였으며, 산업대기 폭로 표면의 인공우수에서의 부식속도는 $3{{\mu}m}/y$로 측정되어 우수한 내후내식 녹층으로 덮혀 있었다. 지속적으로 인공우수에 침적시키면 모든 시편 녹층은 점진적으로 열화되어 모재 철분의 양극산화용해 율속의 부식으로 진전됨을 나타내었다. 내후성 합금성분은 이런 부식의 진전을 지연시키고 있었다. 장기 내식성을 잘 평가하기 위해서는 9년보다 훨씬 장기간 대기폭로된 강재표면과 해당 대기 응축수 모사 수용액을 이용한 전기화학적 측정이 필요하다. 특히 본 측정방법들은 강재 표면의 원하는 부위와 폭로시간대에 거의 비파괴적으로 부식상황과 녹층의 상태와 정량적인 부식속도를 직접 바로 측정할 수 있게 하므로 강재를 사용한 교량, 탑, 건축물 등의 강구조물의 표면에 전기화학적 cell을 구성하고 이동측정기를 사용하면 강구조물의 내후 내식성을 현장즉시 측정 및 평가를 효과적으로 가능하게 할 수 있다. To investigate the long-term corrosion resistance of an uncoated weathering steel, an important outdoor constructional steel material, skyward surfaces of the weathering steel and a control steel initially exposed to rural and industrial atmospheres for 9 years were electrochemically tested in neutral artificial rain in terms of electrochemical potentials, impedances, and anodic potentiodynamic polarization curves. Their results were then discussed. A quite passive and stable rust layer to the artificial rain was well formed on the skyward surface of the weathering steel exposed to the industrial and rural atmospheres, and its corrosion rate in the artificial rain was measured to be about a low $3{{\mu}m}/y$. Continuous immersion of all the weathered surfaces in the artificial rain revealed the gradual degradation of the weathered corrosion layers on the steel, resulting in a cathodically controlled corrosion of the substrate steel by the electrochemical measurements. Alloy components of the weathering steel were found to retard the degradation of the weathered corrosion layers on the steel in the artificial rain. For better corrosion evaluation of the weathering steel, more electrochemical measurements of surfaces that have been exposed for more than 9 years to more closely simulated atmospheric waters are needed. These measurements are almost non-destructive and can provide online and in situ information on the corrosion rate, the development of corrosion and the conditions of rust layers on any interested surface and at any exposure time of the steel, so they can be effectively applicable to the corrosion evaluation of steel structures such as bridges, towers, and architectures by forming an electrochemical cell on an interested structural surface and by using a portable electrochemical instrument.

단백질원이 어분인 조피볼락 치어 사료에 인(P)과 철(Fe)의 보충 효과

박승렬(Sung-Real Park),이상민(Sang-Min Lee),정관식(Gwan-sik Jeong),장영진(Young Jin Chang) 한국수산과학회 양식분과 1997 韓國養殖學會誌 Vol.10 No.3

사료의 단백질이 조피볼락 혈액중 Insulin - like growth factor - 1 ( IGF - 1 ) 및 IGF - binding protein - 3 에 미치는 영향

남택정(Teak Jeong Nam),권미진(Mi Jin Kwon),이상민(Sang Min Lee),박기영(Kie Young Park),김윤(Yun Kim),박승렬(Sung Real Park),변재형(Jae Hyeung Pyeun) 한국수산과학회 2001 한국수산과학회지 Vol.34 No.5

조피볼락을 실험어로 하여 사료 단백질의 함량과 단백질원을 달리하여 공급한 후 동물의 성장인자 중 하나인 Insulin-like growth factor-I (IGF-I)과 IGFBP-3의 혈중농도를 검토하였다. 사료 단백질의 함량이 50%∼60% 급여군에서 성장이 좋았고, 혈액중 IGF-I 농도도 높게 나타났다. 그리고 콘글루텐과 우모분보다 질적으로 우수한 어분, 대두박분, 육분을 첨가한 사료로 사육한 조피볼락의 혈액중 IGF-I과 IGFBP-3가 높은 것으로 나타났으므로, 어류 단백질 대사수준을 파악하는 지표로 활용이 가능하였다. Insulin-like growth factor-I (IGF-I) is a mitogenic peptide with a molecular mass of 7 kDa. It is produced mainly in the liver and has important functions in the regulation of development and somatic growth. Moreover, Serum IGF-I concentration is regulated by the quantity and the nutritional quality of dietary protein. To determine the IGF-I level in Korean rockfish, Sabastes schlegeli, were fed four experiment diets that contained different protein quantities, namely 30%, 40%, 50% and 60% for 70 days. Weight gain of the fish increased depending dietary protein quantity. Also, IGF-I concentrations increased according to dietary protein quantity. Feeding experiments were conducted to examine the effects of dietary protein sources on the serum IGF-I level in Korean rockfish. Fish meal (CO), soybean meal (SM), corn-gluten meal (CGM), meat meal (MM) and feather meal (FM) were used as variable protein sources of the formulated diet. IGF-I concentrations of the CO and MM groups (277.7 ±23.2, 291.5 ±41.2 ng/㎖) were higher than those of the CGM and FM groups (208.9 ±21.3, 217.2 ±38.2 ng/㎖). And IGFBP-3 levels by western blot analysis increased in good protein diets such as in the CO and MM groups. In conclusion, IGF-I may be a sensitive indicator the protein metabolism in fish as well as mammalian.

Submicro-polymer particles bearing imidazoline-2-selenone: dual mode adsorbents with color-sensing for halogens and mercury ions

Choi, Jaewon,Park, So Yeon,Yang, Hye Yun,Kim, Hae Jin,Ihm, Kyuwook,Nam, Jeong Ho,Ahn, Joung Real,Son, Seung Uk Royal Society of Chemistry 2011 Polymer chemistry Vol.2 No.11

<P>Submicron-sized polymer particles (PSE) containing imidazoline selenones were prepared by co-polymerization of styrene derivative (MSE) bearing an imidazoline selenone moiety with 1,4-divinylbenzene (DVB). The size and chemical composition of PSE were controlled by changing the stoichiometric ratios of MSE to DVB. The physical and chemical properties of PSE were characterized by SEM, EDS and elemental analysis. PSE showed an interesting reactivity towards halogens with vivid color-change from white to red-orange, which is attributed to the reaction of selenium in imidazoline-2-selenone with halogens. Acid treatment of PSE generated the hydrophilic red-orange colored particles (PSEA) which showed very selective adsorption properties towards mercury ions with color change to pale yellow. To figure out the origin of color change, model studies were conducted using 1,3-dimethyl-imidazoline-2-selenone. The dimerization of 1,3-dimethyl-imidazoline-2-selenone through Se–Se bond formation by acid-treatment resulted in color change from colorless to red-orange. The coordination-induced cleavage of the Se–Se bond of the dimerized species by mercury ions resulted in color change from red-orange to pale yellow. These observations indicate that hydrophobic PSE and hydrophilic PSEA are efficient systems for adsorption of halogens and mercury ions with a vivid color-detection.</P> <P>Graphic Abstract</P><P>Submicron-sized polymer particles containing imidazoline-2-selenones have been applied as color-sensing adsorbents of halogens and transition metals. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1py00260k'> </P>