온도변화에 따른 주석 도금한 전기 커넥터의 미동마멸 부식 거동

오만진(Man-Jin Oh),강세형(Se-Hyung Kang),이만석(Man-Suk Lee),김호경(Ho-Kyung Kim) 한국트라이볼로지학회 2014 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.30 No.3

In this study, we conduct fretting corrosion tests on tin-plated brass coupons to investigate the effect of temperature on fretting corrosion for various span amplitudes. We prepare a coupled fretting corrosion specimens using a tin-plated brass coupon with a thickness of 10 μm. One specimen is a flat coupon and the other specimen is a coupon with a protuberance in 1 mm radius, which is produced using 2 mm diameter steel ball. We conduct fretting corrosion tests at 25℃, 50℃, 75℃, 100℃ by rubbing the coupled coupons together at the contact between the flat and protuberance coupons. We measure electric resistance of the contact during the fretting corrosion test period. There is increase in resistance with fretting cycles. It is found that rate of increase in electric resistance becomes faster with increase in testing temperature. Magnitude of friction coefficient increases with fretting span amplitudes. And, change in friction coefficient becomes desensitized to the increment in span amplitude. Assuming that failure cycle is the cycle with an electric resistance of 0.01 Ω, we find that failure lifetime (Nf) decreases with increase in testing temperature. Furthermore, based on the assumption that the damage rate of the connector is inversely related to the failure cycle, we calculate the activation energy for fretting damage to be 13.6 kJ/mole by using the Arrhenius equation. We propose a method to predict failure cycle at different temperatures for span amplitudes below 30 μm. Friction coefficients generally increase with increase in span amplitude and decrease in testing temperature.

일정 변위 진폭조건에서의 은도금한 커넥터의 미동마멸부식 거동

오만진(Man-Jin Oh),김민정(Min-Jung Kim),김택영(Taek-Young Kim),강세형(Se-Hyung Kang),김호경(Ho-Kyung Kim) 한국트라이볼로지학회 2014 한국윤활학회지(윤활학회지) Vol.30 No.2

Fretting corrosion tests are conducted with a constant displacement amplitude using silver-plated brass coupons to investigate the effect of contact pressure on fretting corrosion. Three behaviors are identified based on the change in electric resistance and friction coefficient during the fretting test period, and the identified behaviors are dependent on the magnitude of the applied load. The failure cycle (Nf) with an electric resistance of 0.1 D cannot be achieved due to the adhesion behavior of the metal and metal contact under the higher applied load of 0.45 N. This suggests that an average contact pressure higher than 159 MPa for the silver-coated connector is desirable to gain an almost infinite lifetime. The relationship between the electric contact resistance (R) and the average contact pressure (p) can be written as p = 106.2 × Ω?<SUP>1.5</SUP>.

식용유지에 대한 칡뿌리 추출물의 항산화효과

오만진(Man-Jin Oh),손화영(Hwa-Young Son),강재철(Jae-Cherl Kang),이가순(Ka-Soon Lee) 한국식품영양과학회 1990 한국식품영양과학회지 Vol.19 No.5

식물체로 부터 항산화성분을 분리, 이용하고자 칡뿌리 분말에 ethanol, methanol, chloroform, isopropyl alcohol을 가하여 칡뿌리 추출물을 조제하였다. 돈지, 우지, 대두유, 팜유에 0.1% 수준의 칡뿌리 추출물을 첨가하고 60℃, 100℃, 145℃에서 저장하였을때, 시간의 경과에 따른 Po value Co-value, TBA value를 측정하여 칡뿌리 추출물의 항산화 효과를 검토한 결과는 다음과 같다.<br/> 칡뿌리 분말로부터 3단계 용매추출에 의하여 얻어진 추출물의 수율은 2.5%이었고, 0.1%를 첨가하여 60℃에서 가열처리 하였을 때 α-tocopherol 100ppm첨가구와 비슷한 항산화 효과를 나타내었다. 60℃에서 칡뿌리 추출물의 항산화 효과는 우지, 돈지에서 매우 높았고 대두유에서는 효과가 적었으며 100℃에서는 우지>팜유>돈지의 순이었다. 또는 145℃에서 돈지, 팜유, 대두유에 대한 추출물의 항산화 효과는 거의 인정되지 않았으며 온도가 높아짐에 따라 칡뿌리 추출물의 항산화력은 저하되었다. This research was performed to investigate the antionxidative effect of Pueraria root extract on edible oils and fats at various temperature. Antioxidative fractions in Pueraria root were extracted by three consecutive solvent system, i. e. methanol, chloroform and isopropyl alcohol. The yield of extract obtained from Pueraria root powder was 2.5%. Antioxidative. activities of the extracts when added to edible oils and fats were effective than that of 100ppm alpha-tocopherol addition. Antioxidative effect of Pueraria root extract on animal fats were more effective than vegetable oils at 60℃. Antioxidative activity by the peroxide value was higher in the order of tallow, palm at 100℃. The activity of Pueraria root extract was lowered when temperature was increased. It was conclude that extract of Pueraria root has remarkable antioxidative activity. in the oxidation of edible oils and fats.

고온성세균의 β- Galactosidase 에 관한 연구 (Ⅱ) - 효소의 생산 , 정제 및 정제효소의 성질 -

오만진(Man Jin Oh),이종수(Jong Soo Lee),김해중(Hai Jung Kim),김찬조(Chan Jo Kim) 한국미생물생명공학회 1983 한국미생물·생명공학회지 Vol.11 No.1

칡뿌리의 항산화 성분

오만진(Man-Jin Oh),이가순(Ka-Soon Lee),손화영(Hwa-Young Son),김성렬(Seung-Yeol Kim) 한국식품과학회 1990 한국식품과학회지 Vol.22 No.7

연구논문 / 식품부패 및 병원성 미생물에 대한 자소잎 추출물의 항균효과

오만진(Man Jin Oh),이가순(Ka Soon Lee),이주찬(Joo Chan Lee),한규흥(Kyu Heung Han) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 1999 한국식품저장유통학회지 Vol.6 No.2

미생물에 의한 난분해성 유기염소계 오염물질의 분해 -각종 PCBs 및 유기염소계 농약의 분해와 분해산물-

김찬조,오만진,이종수,Kim, Chan-Jo,Oh, Man-Jin,Lee, Jong-Soo 한국응용생명화학회 1987 한국농화학회지 Vol.30 No.1

Alcaligenes aquamarinus에 의한 각종 PCBs와 유기염소계 농약 및 토양중의 PBC-42 분해 등을 검토하고 TLC 등으로 분해산물을 검정한 결과 PCBs에서는 염소화도가 낮은 PCBs가 더 쉽게 분해되었고 유기염소계 농약에서는 p,p'-DDT>r-BHC>Thiolix 순으로 분해되었다. 토양중의 PCB-42의 분해는 살균하지 않은 토양시료에서 $25^{\circ}C$, 25일 배양으로 약 40%가 분해되었다. PCB-42의 분해로 생성된 황색물질의 최대 흡수파장은 pH 4.5에서 258nm와 295nm이었고 분해산물의 일종인 p-chlorobenzoic acid가 TLC와 GC에 의하여 확인되었다. Degradation of polychlorinated biphenyls(PCBs) and organochlorine pesticides by Alcaligenes aquamarinus has been studied and also degradation product of PCB-42 was investigated by TLC and GC. The less chlorinated members of PCBs such as Aroclor 1016 was degraded readily by the strain and rates of the microbial degradation of several organochlorine pesticides were found to decrease in the order of p,p'-DDT, r-BHC and Thiolix. Approximately 40 percent of PCB-42 was degraded when incubated with non-autoclaved soil for 25 days at $25^{\circ}C$. The yellow compound from PCB-42 was tentatively identified as p-chlorobenzoic acid.

당밀주정(糖蜜酒精) 증류폐액(蒸溜廢液)을 이용한 단세포(單細胞) 단백질(蛋白質)의 생산에 관한 연구(제2보) -Candida brumptii 균체(菌體) 생산조건에 대하여-

김찬조,오만진,박수웅,Kim, Chan-Jo,Oh, Man-Jin,Park, Soo-Ung 충남대학교 농업과학연구소 1976 Korean Journal of Agricultural Science Vol.3 No.2

당밀주정증류폐액을 이용하여 분리동정(分離同定)한 효모(酵母)로 SCP 생산에 대한 몇가지 조건과 인체수율을 측정하여 다음과 같은 결과를 얻었다. 폐액의 상징액을 희석하지 않고 그대로 사용하는 것이 가장 효과적이었다. 공시균주(供試菌株)를 배양함으로써 폐액의 BOD와 COD는 각각 약 30% 및 20%정도 감소되었다. 배양조건은 온도 $35^{\circ}C$, pH5.0이 양호하였으며 질소원(窒素源)은 $(NH_4)_2SO_4$와 $(NH_4)_2HPO_4$가 0.2%에서 적당 하였으며 무기 염류는 $K_2HPO_4$를 0.1~0.2%의 첨가가 가장효과적이었다. 균체수율은 약 1.03%이었으며 생산된 균체중의 조단백질(粗蛋白質)은 약 52.65%이었다. Candida brumptii was one of the best isolates which could grow on alcohol distillation slops (reported in the previous paper). Attempts were made to investigate the cultural conditions for cell mass production by this strain, and the results obtained were as follow. The supernatant of the alcohol distillation slops without dilution support ed better growth of the strain than diluted ones. The addition of ammonium sulfate (0.2%), ammonium phosphate (0.1-0.2%), potassium phosphate (0.2%) to the supernatant resulted in positive effects for the growth, among the various inorganic nitrogen and other salts supplements. BOD and COD of the supernatant were reduced approximately 30% and 20%, respectively in 3 days culture. Cell production was maximized when grown at $35^{\circ}C$ and pH 5.0. The yield of cell mass was 1.03% by dry weight and its crude protein content was about 52.65%

대두 ${\alpha}-galactosidase$의 정제 및 성질

금종화,오만진,김성렬,Keum, Jong-Hwa,Oh, Man-Jin,Kim, Seong-Yeol 한국응용생명화학회 1991 Applied Biological Chemistry (Appl Biol Chem) Vol.34 No.3

To elucidate enzymatic properties of ${\alpha}-galactosidase$ (EC 3, 2, 1, 22) from germinated soybean, changes in the enzyme activities and oligosaccharide contents during germination of soybean were determined. ${\alpha}-Galactosidase$ from germinated soybean was purified by ammonium sulfate fractionation, ion exchange chromatography and gel filtration. Their chemical and enzymatic properties was investigated. ${\alpha}-galactosidase$ activity of sobeam was maximized when it was germinated at $25^{\circ}C$ for 120 hour. Raffinose and stachyose in soybean were decomposed completely after 96 hours and 120 hours of germination, respectively. Soybean ${\alpha}-galactosidase$ was purified by 6.6 fold by ammonium sulfate fractionation, ion exchange chromatography on DEAE-Cellulose and Sephadex A-50, and gel filtration on Sephadex G-150. Its specific activity was 825 Units/mg protein and the yield was 2.5% of the total activity of crude extracts. The purified ${\alpha}-galactosidase$ of soybean was found to be homogeneous by polyacrylamide gel electrophoresis and by HPLC. Isoelectric point of soybean ${\alpha}-galactosidase$ was determined analytical isoelectric focusing to be pH 4.8. The soybean ${\alpha}-galactosidase$ was monomeric and its molecular weight was estimated to be 30,000 by SDS-PAGE. The optimal temperature and pH for the soybeam ${\alpha}-galactosidase$ activity were $40^{\circ}C$ and pH 6.0 and 75% of its activity was lost by heating at $60^{\circ}C$ for 10 min. The enzyme was appeared to have higher affinity to raffinose than to stachyose. The Km value of soybean enzyme was 5.3 mM for ${\rho}-nitrophenyl-{\alpha}-D-galactopyranoside$ and the activation energy on PNPG was calculated to be 13.02 Kcal per mole. 대두 발아 과정 중의 ${\alpha}-galactosidase$를 추출하여 염석, 이온교환 크로마토그래피 및 겔 여과 등의 방법으로 정제한 후 정제효소의 효소학적 성질을 검토하였다. 대두 ${\alpha}-galactosidase$의 활성은 $25^{\circ}C$에서 120시간 발아시켰을 때 가장 높았으며, 대두 중의 raffinose는 96시간, stachyose는 120시간 발아시켰을 때 완전히 분해되었다. 대두 ${\alpha}-galactosidase$는 황산암모늄염석, DEAE-Cellulose 및 DEAE-Sephadex A-50 이온교환 크로마토그래피, Sephadex G-150 겔 여과 등에 의하여 비활성은 825U/mg protein으로써 6.6배까지 정제되었으며 수율은 2.5%이었고 HPLC와 PAGE에 의하여 순도를 확인하였다. 정제효소의 등전점은 pH 4.8이었고, 분자량은 30,000인 monomer이었으며 정제효소의 최적작용 PH는 6.0, 최적작용온도는 $40^{\circ}C$ 이었고, $60^{\circ}C$에서 10분 처리시 25%의 잔존 활성을 나타내었다. 정제효소는 stachyose보다 raffinose를 쉽게 분해하였으며 PNPG에 대한 Km값은 5.3 mM, 활성화 에너지는 13.02 cal/mole이었다.

금강수질(錦江水質)에 관(關)한 조사연구(調査硏究)

박종성,오만진,Park, Jong-Seong,Oh, Man Jin 충남대학교 농업과학연구소 1979 Korean Journal of Agricultural Science Vol.6 No.1

금강수계(錦江水系)의 신탄진(新灘津)등 6개지점(個地點)을 조사지역(調査地域)으로 설정(設定)하고 1977년(年) 9월(月)부터 1978년(年) 8월(月)까지의 수질(水質)을 분석(分析)한 결과(結果)는 다음과 같다. 1) pH, $NO_3-N$, $NO_2-N$는 조사지점별(調査地點別), 월별(月別)차이가 없었다. 2) 부여(扶餘), 강경지점(江景地點)의 BOD는 각각 3.9~5.6, 5.6~6.0ppm으로 상수도원(上水道源) 오염한계(汚染限界)에 도달(到達)하였다. 3) 대전천(大田川)이 합류(合流)하는 매포지점(梅浦地點)의 BOD는 신탄진지점(新灘津地點)의 BOD에 비(比)하여 1977년(年) 9월(月), 10월(月), 11월(月)에 각각 1.9, 3, 2.1배(培) 증가되었다. 4) 용존산소(溶存酸素)는 $7.6{\pm}3.8ppm$으로 수온(水溫)의 변화(變化)와 지점별(地點別) 차이가 있었다. 5) 경도(硬度), 부유물질(浮游物質), $NH_3-N$는 조사지점별(調査地點別), 월별(月別)로 차이가 있었다. Water of river gets great concern about its quality, which might be polluted with pollutant from various industrial plants booming along the river sides in recent years. As a first step to prevent any applciable damage due to water pollution, survey on the water quality of Keum river at Sintanjin, Maepo, Taepyongri, Kongju, Puyeo and Kanggeng, six regions was conducted during september, 1977 through august, 1978 and the results were summarized as follow: 1. There were no significant regional and monthly difference in pH, $NO_2-N$, and $NO_3-N$ of water. 2. The BOD at Puyeo, Kanggeng was 3.9 to 5.6, 5.6 to 6.0 ppm, respectively, and those values reached the limiting level for tap water sources. 3. The BOD at Maepo, where Daejeon streams meet, was found 1.9, 3.0, and 2.1 times higher than those at Sintanjin region, during september, october and november, respectvely. 4. Content of DO was $7.6{\pm}3.8ppm$ in all surveyed regions and varied with water temperature and regional difference. 5. There were found regional difference and monthly difference in water hardness, suspended solid and $NH_3-N$.