천연 갈변 억제제 개발을 위한 양파,사과 및 감귤 과피 추출물의 항산화 및 갈변 저해 효과

장민선 ( Min Sun Chang ),안세진 ( Se Jin An ),정문철 ( Moon Cheol Jeong ),김동만 ( Dong Man Kim ),김건희 ( Gun Hee Kim ) 한국식품영양학회 2011 韓國食品營養學會誌 Vol.24 No.3

This study was carried out to investigate antioxidative properties of various extracts and antibrowning effects of extracts in apple slices were investigated by ΔE value and PPO relative activity. Apples were cut into 1.5 ㎝ thickness and they were dipped in 1% extract solutions(OW: water extracts of onion, OE: 80% EtOH extracts of onion, AW: water extracts of apple, AE: 80% EtOH extracts of apple, MW: water extracts of mandarin orange peel, ME: 80% EtOH extracts of mandarin orange peel) for 1 min. OW showed higher than the other treatments for total phenolic contents(94.35 ㎎/g), PPO inhibition(74.00%). And the highest DPPH free radical scavenging activity(40.27%) measured in ME. ΔE value of apple slices dipped in MW was 2.37 whereas ΔE value of apple slices dipped in AW was 12.12. These results suggest that onion and mandarin orange peel extracts should be a potential source for controlling browning during storage of apple slices.

Bioconversion of ginsenoside Rc into Rd by a novel α-L-arabinofuranosidase, Abf22-3 from Leuconostoc sp. 22-3: cloning, expression, and enzyme characterization.

Liu, Qing-Mei,Jung, Hae-Min,Cui, Chang-Hao,Sung, Bong-Hyun,Kim, Jin-Kwang,Kim, Song-Gun,Lee, Sung-Taik,Kim, Sun-Chang,Im, Wan-Taek N.V. Swets en Zeitlinger 2013 Antonie van Leeuwenhoek Vol.103 No.4

<P>A novel α-L-arabinofuranosidase (Abf22-3) that could biotransform ginsenoside Rc into Rd was obtained from the ginsenoside converting Leuconostoc sp. strain 22-3, isolated from the Korean fermented food kimchi. The gene, termed abf22-3, consisting of 1,527 bp and encoding a protein with a predicted molecular mass of 58,486 Da was cloned into the pMAL-c2x (TEV) vector. A BLAST search using the Abf22-3's amino acid sequence revealed significant homology to that of family 51 glycoside hydrolases. The over-expressed recombinant Abf22-3 in Escherichia coli BL21 (DE3) catalyzed the hydrolysis of the arabinofuranoside moiety attached to the C-20 position of ginsenoside Rc under optimal conditions of pH 6.0 and 30 C. This result indicated that Abf22-3 selectively converts ginsenoside Rc into Rd, but did not catalyze the hydrolysis of glucopyranosyl groups from Rc or other ginsenosides such as Rb1 and Rb2. Over-expressed recombinant enzymes were purified by two steps with amylose-affinity and DEAE-cellulose chromatography and then characterized. The kinetic parameters for α-L-arabinofuranosidase showed apparent Km and Vmax values of 0.95 0.02 μM and 1.2 0.1 μmol min(-1) mg of protein(-1) against p-nitrophenyl-α-L-arabinofuranoside, respectively. Using a purified MBP-Abf22-3 (10 μg/ml), 0.1 % of ginsenoside Rc was completely converted to ginsenoside Rd within 20 min.</P>

A rare case of extensive papillary muscle calcification in senile cardiac calcification syndrome

김은진;송봉근;강민호;손형래;홍수민;박동원;허승혜;김계연;최석구 인제대학교 2011 仁濟醫學 Vol.32 No.-

광범위 유두근 석회화는 흔하지 앉으며, 원인과 임상적 중요성에 관한 문헌만 드물게 찾아볼 수 있다. 반면에 작은 석회 침착은 노인에서 흔하며 심장 첨부에 주로 나타난다. 유두근 석회화는 관상동맥질환, 확장성 심근병증, 승모관 질환, 고칼슘혈증, 그리고 말기신부전에서 인산칼슘의 중가와 연관성이 있다. 저자는 심장초옴파와 MDCT를 통해 진단된 전외측 유두근의 광범위 석회화의 드문 사례가 있어 보고한다.

CRACK 開口變位에 기초한 微小疲勞크랙 전파法則의 考察

김민건,지정근 江原大學校 産業技術硏究所 1993 産業技術硏究 Vol.13 No.-

Bending fatigue tests were carried out on the specimenes with tow different strength levels in order to investigate small crack growth rate. The main results obtained are as follows : (1) Small crack growth law, da/dn = Cσ?a is useful several materials, but is not the rule applicable to all cases generally. (2) When da/dn in several specimens are equal. COD near the crack tip are also nerarly equal. (3) Crack tip opening displacement (CTOD) is the main factor to control the small crack growth rate, and da/dn ? CTOD comes into being between the two. Accordingly, da/dn = c(σ?/σ)?a? shows the small crack growth rate being reflected crack closure phenomenon.

마하피닝 처리에 의한 기계구조용 합금강의 피로균열전파 지연효과

김민건,임복규,박홍기,황중각 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

Mach peening treatment is one of the various kinds of techniques to improve the fatigue properties. The mach peening process gives high-level work hardening and compressive residual stress near the surface layer, improving the fatigue strength. In addition, this treatment reduces slip bands that initiate the fatigue cracks near the surface. During impingement, a plastic indentation surrounded by a plastic zone is formed. Mach peening treatment characteristic is less energy consumption and is an environmental friendly processing methods that is not accompanied by pollution. It is machining process that can prevent fatigue fracture beforehand in structure using already as well as process of production. The test results showed that fatigue crack propagation delay appeared by drilling type 43%, mach peening type 110%.

실린더타입 도어클로저의 구조 및 내구해석

김민건,정구현,박찬원 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.3

The door closer is a typical system which consists of spring and damper. The door closer is a device to close the door more slowly. The virtual prototypes of cylinder-type door closer are developed. The simulations of virtual prototype are performed to obtain the load history of the guide pin. The structural strength assessment of the guide pin is performed to verify a design safety. The fatigue life and damage of the guide pin are predicted using a FEMFAT 4.3h based on the finite element analysis.

마하피닝 처리에 의한 기계구조용 합금강의 피로균열전파 지연효과

김민건,임복규,박홍기,황중각 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.A

Mach peening treatment is one of the various kinds of techniques to improve the fatigue properties. The mach peening process gives high-level work hardening and compressive residual stress near the surface layer, improving the fatigue strength. In addition, this treatment reduces slip bands that initiate the fatigue cracks near the surface. During impingement, a plastic indentation surrounded by a plastic zone is formed. Mach peening treatment characteristic is less energy consumption and is an environmental friendly processing methods that is not accompanied by pollution. It is machining process that can prevent fatigue fracture beforehand in structure using already as well as process of production. The test results showed that fatigue crack propagation delay appeared by drilling type 43%, mach peening type 110%.

임계정류피로크랙의 하한계 전파조건의 정량적 고찰

김민건 江原大學校 産業技術硏究所 2010 産業技術硏究 Vol.30 No.B

Since the propagation of a short fatigue crack is directly related to the large crack which causes the fracture of bulk specimen, the detailed study on the propagation of the short crack is essential to prevent the fatigue fracture. However, a number of recent studies have demonstrated that the short crack can grow at a low applied stress level which are predicted from the threshold condition of large crack. In present study, the threshold condition for the propagation of short fatigue crack is examined with respect to the micro-structure and cyclic loading history. Specimens employed in this study were decarburized eutectoid steels which have various decarburized ferrite volume fraction. Rotating bending fatigue test was carried out on these specimens with the special emphasis on the "critical non-propagating crack length" It is found that the reduction of the endurance limit of their particular micro-structures can be due to the increase of the length of critical non-propagating crack, and the quantitative relationship between the threshold stress σ_(wo) and the critical non-propagating crack length Lc can be written as σ_(wo)^(m) · Lc = C where m,C is constant. Further experiments were carried out on cyclic loading history on the length of critical non-propagating crack. It shown that the length of critical non-propagating crack is closely related to cyclic loading history.

Cyclosulfamuron과 Pyribenzoxim의 莖葉處理에 따른 논 雜草 防除效果에 관한 硏究

金健敏,金武成,盧泳德 慶熙大學校 1997 論文集 Vol.26 No.-

Experiments were carried out to evaluate weed control performance of Cyclosulfamuron and Pyribenzoxim by foliar application, especially for direct seeded rice. In addition, the combinations of the herbicides and water managements were tested for the improvement of the herbicidal activity. Herbicidal effect of Cyclosulfamuron was excellent for B. tripartita, B, frondosa, fair or fairly good for A. indica, and C. cerotinus, and good for E. crus-galli, L. prostrata, S. juncoides, and A. keisak. Herbicidal effect of Pyribenzoxim was excellent for B. tripartita, B. fonndosa, A. keisak, and A. indica, fairly good for E. crus-galli, L. prostrata and poor for s. juncoides, and C. cerotinus. The foliar treatment of two herbicides were the most effective when irrigated 3 days after treatments. The herbicidal effects became poor when saturated condition was maintained, especially E. crus-galli and S. jucoides. Both Cyclosulfamuron and Pyribenzoxim were very effective for the control of B. tripartita and frondosa even under very low concentrations. But the higher rates of Pyribenzoxim are to be used for the better control of E. crus-galli and L. prostrata. Combination treatments of the two herbicides could extended the weed control spectrum. In addition the combination treatments had some positive effects in controlling L. prostrata, S. juncoides and A. keisak

銅 表面의 화학 腐蝕에 의한 蝕刻 패턴 연구

김민건,서봉원 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.B

In order to observe the pattern forming of copper plate and chemical corrosion reaction, a study on the effect of the process parameters on the formation of micro-pattern by a photochemical etching of copper plate was carried out. The results are as follows : 1) Etching rate increases as the concentration of etchant increases under the regular condition of the temperature by the increasing of diffusion rate to surface. 2) Etching rate increases as the temperature of etchant increases by the fast acting of the material delivery of diffusion to surface under the regular condition of concentration. 3) It was found that etching speed increases as the material delivery of convection rising increased when the aeration speed of etchant increases. This result was from the fact acted by the material delivery of convection rising rather than material delivery of diffusion to the surface.