아닐린 단량체를 함유한 염산 수용액에서 스테인레스강 전극의 부식특성

조정환,이호근 고신대학교 자연과학연구소 1994 고신대학교 자연과학연구소 논문집 Vol.4 No.-

전도성 고분자인 폴리아닐린의 전기화학적 합성 용액인 1 M HCI + aniline의 혼합용액에서 스테인레스강의 부식 특성을 조사하였다. 스틸의 부식특성에 관한 aniline의 영향을 이해하기 위하여, 위의 혼합용액과 1 M HCI 수용액에서 스틸의 부식특성이 polarization measurements를 통하여 수행되었다. 또한 스테인레스 스틸의 내부식성을 향상시키기 위해 Cr^(6+)가 포함된 황산수용액에서 일정한 시간 간격의 potential pulse를 가하여 강 표면의 전기화학적 변형을 시도하였으며, 전기화학적 부식 측정을 통하여 표면처리된 스테인레스강의 증가된 내부식성을 확인하였다. Corrosion charateristics of stainless steels in the aqueous mixture of 1 M HCI + aniline, which has been used as a solution for electrochemically synthesizing conductive polyaniline, were investigated, Polarization measurements were carried out in order to understand the effect of aniline to corrosion characteristics of stainless steels in the solution mixture. Also, the surface of the steel was electrochemically modified by applying potential pulse with a constant interval to the steel immersed in the sulfuric acid containing Cr^(+6) in order to improve corrosion resistivity, and the electrochemical corrosion measurements confirms improvement of the corrosion characteristics of the surface modified steel.

기-액계면 흡착에 의한 계면활성제 및 중금속분리

이근희,남상진,김병조,박경기,박종태,신정호 釜山大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.53 No.-

CTAB에 의한 CuS 침전 미립자의 응집과 기포 흡착특성을 고찰하였다. CTAB의 기포흡착은 Langmuir흡착식을 따르며, 포말간 본체액의 동반을 고려한 회분해석으로부터 구한 흡착열은 3700cal/mol로 나타났다. CTAB에 의한 CuS미립자의 기포흡착은 기포-입자간 충돌흡착으로 설명되었고, 흡착분리에 대한 최적 농도비는 CuS의 최적 응집농도비와 일치하였으며, 그 값은 [CTAB] 대 [CuS]가 0.1로 얻어졌다. 기포에 의한 포집효율은 pH와 CTAB농도 등에 의존하나 공기의 유량에는 무관하였으며, 최대 포집효율은 최적 첨가농도에서 0.0002로 나타났다. 또한 Cu-Cd-Zn 황화물의 혼합계에서 CTAB를 사용한 기포흡착의 경우 ZnS의 선택적 분리가 가능하였다. The characteristics of the bubble adsorptive separation of CTAB(cetyltrimethyl- ammonium bromide) and CuS precipitates was investigated. The Langmuir adsorption equation was adequate at very low concentration of CTAB, and the adsorption heat was determined from the batch analysis considering the bulk liquid accompanied between bubbles. The adsorption mechanism was explained with the collision adsorption between bubbles and precipitate particles. The optimum concentration ratio of [CTAB] to [CuS] for adsorptive separation was 0.1 and coincided with the ratio for the coagulation of particles. The collection efficiency was depended on pH and CTAB concentration but not the air flow rate, and the maximum efficiency was 0.0002. The selective separation of ZnS from the mixture of Cu-Cd-Zn sulfides was able by the bubble adsorption with CTAB.

전류모드방식 적분기의 구조개선을 통한 성능비교

이근호,조성익,방준호,김동용 全北大學校 論文集 Vol.42 No.-

In this paper, a CMOS fully-differential complementary current-mode integrator adequate to design low-voltage, low-power and high frequency application circuit. The designed fully-differential complementary current-mode integrator has a new architecture. When the improved integrator is compared with proposed current-mode integrator, the new integrator has lower power dissipation and higher frequency range. The small signal analysis results are showed in table.1 with several improved characteristics. And the results of PSPICE simulation using ORBIT company's 1.2㎛ CMOS n-well processing parameter shows fig. 3.

벼 재배기간중 전남동부지역 농촌하천의 수질과 분포초종

이도진,조주식,국용인,안호근 한국환경농학회 2003 한국환경농학회지 Vol.22 No.1

전남 동부권에 위치하는 농경지 주변 4개 하천에 대하여 벼 재배기간을 전후한 시기에 하천수질의 특성과 분포하는 초종을 조사한 결과는 다음과 같다. 하천수질 특성은 다양하였으며 조사기간중 각 하천수의 pH는 6.5~8.3 범위였고, EC는 벌교천(162~4,910 μS/cm)에서 가장 높았으며 보성천(114.7~286.6 μS/cm), 송광천(74.8~147.4 μS/cm), 이사천(61.6~82.1 μS/cm)순이었다. 조사기간중 총질소 함량은 보성천(1.9~7.4 mg/L), 벌교천(2.1~3.9 mg/L), 송광천(2.4~3.4 mg/L), 이사천(1.7~2.6 mg/L)순으로 호소수질 환경기준 1등급(0.2 mg/L)과 농업용수 수질기준(1 mg/L)을 모두 초과하였다. 그 밖의 대부분 조사항목(K, Ca, Mg, Na, Cl^- 등)은 하천에 따른 함유량 고저 차이는 있었으나 모내기를 전후한 시기에 영양염류 함량이 가장 높게 나타나 보성천에서는 5월, 송광천과 이사천에서는 6월이었다. 4개 하천의 조사지점에서 관찰된 초종수는 모두 16과 30종이었으며 송광천, 보성천, 이사천, 벌교천에서 각각 18종, 19종, 15종 및 5종으로서 다년생은 17종, 일년생과 2년생은 13종이 출현하였다. 침수성 초종은 검정말, 말즘, 물수세미, 부유성 초종은 개구리밥과 좀개구리밥, 추수성 초종은 갈대, 고마리, 미나리, 여뀌, 줄 등이 관찰되었다. 물가와 주변에서는 개구리자리, 개피, 달뿌리풀, 돌소리쟁이, 물억새, 미국가막사리, 바늘골, 방동바니대가리, 뱀딸기, 사마귀풀, 삿갓사초, 살갈퀴, 선피막이, 소리쟁이, 쇠방동사니, 여뀌바늘, 큰도꼬마리, 토끼풀, 환삼덩쿨, 황새냉이 등의 20종이 관찰되었으며 그 중 고마리, 소리쟁이, 환삼덩쿨은 하천의 모든 조사지점에 출현하였다. The characteristic of the quality of stream water and the nlparlan vegetation during rice cultivation in the rural area of the eastern Jeonnam province was surveyed from April to November, 2000. The water quality of the streams during rice cultivation was variable. The pH of these water bodies ranged from 6.5~83. Electro conductivity (EC) at each water body ranged from 162~4,910 μS/cm for Beolgyo-cheon, 114.7~286.6 μS/cm for Boseong-cheon, 74.8~147 μS/cm for heon, and 61.6~82.1 μS/cm for Isa-cheon. Total nitrogen and other parameters (K, Ca, Mg, Na, CT, SS) were higher at May (Boseong-cheon) through June (Songgwang-cheon, Isa-cheon) during the transplanting season than these same parameters at August, October and November. Thirty weed species of sixteen families were found in the survey areas of Songgwang-cheon, Boseong-cheon, Isa-cheon and Beolgyo-cheon. Nine annual weeds, four biennial weeds, and seventeen perennial weeds were found, several different life forms were identified. Of those species three were submerged, two were free floating, five were emerged, and twenty were water-side weeds.

우리나라 신부화의 연대별 변천에 관한 연구

이원영,조근호,박천호 한국화훼연구회 2001 화훼연구 Vol.9 No.1

This study focuses on changes in the kinds of flowers, colors, shapes of bridal bouquet in Korea for 50 years from 1950's to 1990's. The results show that two to three kinds of flowers were used in 1960's and 1970's, but various materials were used in 1980's and 1990's. White chrysanthemums rank first in 1950's and 1960's, carnations in 1970's, but roses and cymbidiums in 1980's, and use of cymbidiums, roses, and denphalae increased in 1990's. When it comes to foliage, camellia leaf used most frequently until 1960's and Asparagus in 1970's, but use of various tropical foliage such as scindapsu, ivy, Rumora fern increased in 1980's. In colors, white was most preferred in 1950's and 1960'sl pink was added in 1970's, but both white and pink were used in bouquet and boutonniere in 1990's. In shape, large arm bouquet was most preferred in 1950's. Round bridal bouquet with long asparagus stem was most favorite style in 1960's and 1970's, cascade shape and empire bouquet in 1980's, and various bridal bouquet such as cascade, round, triangular and free style in 1990's. In boutonniere they used triangular most frequently.

醮禮山 소나무林의 山火地의 二次遷移

金源,張根亨,曺英鎬,沈學輔 慶北大學校 1992 論文集 Vol.52 No.-

This report is an investigation of revestagation and secondary succession in the burned area. The forest fire occurred in Mt. Ch'olye on April, 1989. After logging of the burned pine tree, the seedlings of Pinus koraiensis were planted by the replaceable plant in there. The results are summarized as follows : Dorminant species in the first year(B-1) after fire were Miscanthus sinensis var. purpurascens, Carex humilis and Duchesnea chrysantha and those in the second year(B-2) after fire Miscanthus sinensis var. purpurascens, Carex humilis and Lespedeza cyrtobotrya. the biological spectra in both burned and unburned areas were H-D_1-R_5-e type. The indices of similarity showed that B-1 and B-2 was 0.667, B-1 and U 0.526, and B-2 and U 0.500. Degree of succession(DS) was 181, 345, 1090 and species diversity(H) 2.35, 2,73, 2.54 and evenness index(e) 0.61, 0.73, 0.73 and dominance index(C) 0.17, 0.11, 0.15, in B-1 and U site, respectively. Biomass of B-2 site was higher than that of B-1 site. Litter amount(kg/m^2) of burned and unbrurned areas were 0.017 and 0.863. Soil pH, content of total nitrogen, organic matter, organic carbon, and water holding capacity of burned area were higher than those of unburned area while content of available phosphorus, exchangeable pottassium, C/N ratio, and water content of unburned area were higher than those of burned area, respectively.

내열성 Chitinase 생산균주의 분리 및 효소생산 특성

홍범식,윤호근,신동훈,조홍연 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

자연계 고온환경으로부터 내열성 chitinase 우수하고 반응산물로 N-acetyl-D-glucosamine 이량체(GlcNAc)_2를 생산하는 균주를 분리 선별하고 Bacillus licheniformis KFB-C14로 동정하였다. 선별균주의 효소생산 특성은 탄소원으로서 효소기질인 colloidal chitin이 첨가될 때만이 생합성이 유도되었으며 유도제의 첨가시기에 의해 효소생산이 크게 영향을 받았다. 각종 무기, 유기태 질소원 중 yeast extract가 활성과 비활성을 각각 약 2배 증가시켰으며 높은 친화도를 나타내었다. 균의 최대생육과 효소의 최대생산온도는 55℃이었다. 본 균주의 내열성 chitinase 생산에 미치는 최적배양조건은 1.2% colloidal chitin, 0.15% K_2HPO_4, 0.05% KH_2PO_4 0.01% MgSO_4·7H_2O, 0.1% yeast extract, pH 6.5의 배지를 55℃, 150rpm에서 40시간 회전진탕배양 하였을 때로 3.89 units/ml의 효소활성과 7.4 units/mg의 비활성을 나타내었다. A strain capable of producing thermostable chitinase suitable for chitooligosaccharide production was isolated from high temperature environment and identified as Bacillus licheniformis. The chitinase from Bacillus licheniformis KFB-C14 was only induced by addition of colloidal chitin into the basal medium as carbon source, showing the decrease of the chitinase production by supplemental addition of other carbon sources into the medium containing 1.0% colloidal chitin. Among organic and inorganic nitrogen sources, yeast extract was the most effective for the increase of total activity and specific activity, and had high affinity for the enzyme production. The optimum temperature of cell growth and thermostable chitinase production was 55℃. The optimum culture medium was composed of 1.2% colloidal chitin, 0.15% K_2HPO_4, 0.05% KH_2PO_4 0.01% MgSO_4·7H_2O, 0.1% yeast extract (pH 6.5). Bacillus licheniformis KFB-C14 produced the thermostable chitinase of 3.89 units per culture fluid and 7.4 units per mg protein under rotary shaking at 150 rpm for 40 hr.

복어중독에 의한 가사 상태에서 소생한 1예

송승찬,신진호,강석우,박경남,최호순,박근태,문희식,기춘석,이성희,윤병철,노우균,조균석,이민호 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.3

Tetrodotoxin is a neurotoxin produced by about 90 species of puffer fish and causes paralysis of central nervous system and peripheral nerves by blocking the movement of all monovalent cation. Ingestion of tetrodotoxin produces clinical manifestations such as paresthesias(within 10-45 min), vomiting, lightheadedness, salivation, muscle twitching, dysphagia, difficulty in speaking, convulsion and death that expressed by cardiopulmonary arrest with loss of brain stem reflex sometimes. Tetrodotoxin prevents or delays ischemia induced neuronal death by way of following 3 mechanisms. Firstly, it reduces the energy demand of the brain tissues. Secondly, it delays or even prevents anoxic depolarization. Finally, it deminishes ischemia induced cell swelling and cerebral edema. We report a case of puffer fish poisoning which presented with cardiopulmonary arrest and loss of brain stem reflex, but completely recovered by aggressive cardiopulmonary resuscitation.

방사선 조사에 의한 흰주 난포의 퇴축과 난포세포의 방사선 감수성

김수일,한승로,조근자,허대영,이영호,조문준,김무강,김원식 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

The aim of this study were to investigate radiation-induced atresia and radiation susceptibility in the rat ovary morphologically. Female rats (Sprague Dawley strain) of 4 weeks old were irradiated with dose of 4 Gy and 8 Gy, and sacrificed at hour 6, 12, and 24 after radiation. The H & E stain, the TUNEL method (ApopTag kit) and transmission electron microscopy (TEM) were used. In light microscopic observation, the number of atresia of ovarian follicles were increased significantly at 6h after irradiation (p<0.01). There was no significant difference between 4 Gy and 8 Gy irradiated groups. In TEM observation, granulosa cells in radio-sensitive follicles were characterized by several structural features including condensation of nuclear chromatin granules, nuclear fragmentation and apoptotic body formation. An apoptotic cell is observed to have been phagocytosed by a normal granulosa cell. Granulosa cells in radio-resistant follicles were characterized by several structural features including nuclear indentation, partial condensation of chromatin granules, mitochondrial swelling, dilatation of RER cisterns, accumulation of dense irregular masses, accumulation of lipid droplets, and increased lysosomal bodies. Number of gap junctions between granulosa cells were decreased, and intercellular space were widen than that of control animals. These findings were prominent at 6h after irradiation and were diminished at 12h and 24h after irradiation. With these results, it was concluded that radiation-induced follicular cell apoptosis and ovarian follicular atresia in rat ovary increased considerably at 6h after irradiation. Further studies are needed to reveal the more extensive differences between radiosensitive and radioresistant follicular granulosa cells.

플라보노이드의 세포 신호전달 조절

이응룡,강근호,강용진,김우열,최혜연,김봉우,정효순,조쌍구 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

Many studies revealed the neuroprotective, cardioprotective, and chemopreventive actions of dietary flavonoids. The plausible mechanistic interpretation of the various effects of flavonoids was concentrated on the anti-oxidant or free radical-scavenging properties of these phytochernicals, both in model systems and under in vivo conditions. While there has been a major focus on the anti-oxidant properties. there is an emerging view that flavonoids and their in vivo metabolites. do not act as conventional hydrogen-donating anti-oxidants. but they may exert regulatory functions in cells through actions at protein kinase or lipid kinase signaling pathways. Flavonoids and more recently their metabolites. have been reported to act at phosphoinositide 3-kinase(PI 3-kinase). Akt/protein kinase B(Akt/PKB), protein kinase C (PKC), mitogen activated protein kinase(MAP kinase), and various tyrosine kinases signaling cascades. Inhibitory or stimulatory actions at these pathways are likely to affect cellular function profoundly by altering the phosphorylation state of target molecules and by modulating gene expression. A clear understanding of the mechanisms of action of flavonoids, either as anti-oxidants or modulators of cellular signaling pathways, and the influence of their metabolism on these properties are key to the evaluation of these potent biomolecules as anti-cancer agents, cardio-protectants, and inhibitors of neurodegeneration.