가스터빈용 소재 IN 738LC 합금의 미세조직 열화거동

유정훈,주성욱,신기삼,김의현,정진성,장성호,송기욱,하정수 국립7개대학공동논문집간행위원회 2002 공업기술연구 Vol.2 No.-

IN 738LC, used as gas-turbine for power generation, was heat treated at 750℃, 850℃, 950℃ for 1000, 2000, and 4000 hrs. and the microstructural evolution are examined using optical microscope, XRD, SEM/EDS. For comparison, part of gas turbine used for 18439 hours for power generation was also examined. The results showed γ´, the main strengthening elements in this alloy, was about 300 nm and was about 56% in as-cast samples. The volume fraction of γ´peaked at 2000 hours at 750℃ and then decreased at further or longer heat treatment. The average diameter of the γ´ which was about 200 nm increased to about 1㎛. Carbides were formed at dendrite, cell, or grain boundaries which was ascribed to the segregation caused by solute redistribution during solidification. It was found that the at low temperature, M_6C type carbides formed, whereas carbides of M_23C_6 type formed at higher temperature, or at longer degradation.

Kamut (Triticum turgidum spp.) 식빵 급여가 고지방식이 유도 비만 C57BL/6 마우스에 미치는 효과

정현기(Hyun Gi Jung),백지윤(Ji Yun Baek),최예정(Ye Jung Choi),강기성(Ki Sung Kang),김현영(Hyun Young Kim),김지현(Ji Hyun Kim),최진상(Jine Shang Choi) 한방비만학회 2021 한방비만학회지 Vol.21 No.2

Objectives: The purpose of this study was to investigate the effect of white pan bread added with Kamut (Triticum turgidum spp.) on high fat diet (HFD)-induced obese C57BL/6 mice. Methods: The white pan bread or white pan bread with Kamut (BK) were administered for 8 weeks in HFD-induced obese C57BL/6 mice. To evaluate the effect and its mechanisms of BK on obese mice, we measured body weight change, serum lipid profiles, histopathological analysis, and protein expression of CCAAT/enhancer binding protein-α (C/EBPα) in the liver. Results: Administration of BK significantly decreased body weight in HFD-induced obese mice. In addition, BK-administered group significantly reduced serum total cholesterol, glucose, and high-density lipoprotein cholesterol levels compared with the HFD-induced control group. The HFD-induced mice had damaged liver tissue and increased the size of adipose tissue, but BK-administered group attenuated liver damage and decreased the size of adipocyte. Furthermore, administration of BK significantly down-regulated C/EBPα in the liver compared with HFD-fed mice. In particular, BK-administered group has higher inhibited body weight, serum lipid profiles, and C/EBPα expressions than white pan bread-administered group. Conclusions: This study demonstrated that administration of BK attenuated HFD-induced obesity by regulation of C/EBPα than consumption of white pan bread. Therefore, BK could be developed as a bread for prevention of obesity.

Quality Characteristics of White Pan Bread Using Whole Wheat (Triticum aestivum) Flour

Hyun-Gi Jung,Jine-Shang Choi 경상대학교 농업생명과학연구원 2019 농업생명과학연구 Vol.53 No.6

Five-color bread was prepared by adding herb powder to Korean whole wheat triticum aestivum flour and the quality of baking was analyzed. The pH of the control bread was 6.15±0.12 while that of the whole wheat flour test group was 6.35±0.11, 6.29±0.12, 6.36±0.12, 6.19±0.11, and 6.01±0.13, respectively. The L value of the control bread was 67.78±0.03 and that of the whole wheat flour test group was 69.66±0.02, 60.01±0.12, 64.23±0.01, 63.34±0.01, and 61.64±0.04, respectively. The water activity was slightly increased at 2 days of storage due to the difference in water absorption and water retention. However, on the third day, the water transfer phenomenon in the bread showed water activity decrease in all wheat flour test groups. On the 1st day of the whole wheat flour test bread, the hardness values were 186.86±4.81, 165.89±3.73, 189.71±3.32, 198.38±2.19, and 184.29±3.40 g/cm2, respectively, and that of the control group was 138.84±3.72 g/cm2. The hardness of the control group and the whole wheat flour test group showed a significant difference. The internal structure of the bread in the whole wheat flour test group (100x, 500x) was not smoother than the control’s. The swelling degree of the starch particles and the cracking of the crumbs were confirmed by the adding of five-colored herbs to whole wheat flour.

Quality Characteristics of Frozen Dough and White Pan Bread with Lily (Lilium lancifolium Thunb.) as Additive

Hyun-Gi Jung,Jine-Shang Choi 경상대학교 농업생명과학연구원 2021 농업생명과학연구 Vol.55 No.1

Attempts to increase the usability of lilies led us to prepare pulverized lily bulbs, which we then added to bread flour to bake white pan bread. The properties of the frozen dough and the quality characteristics of the bread were analyzed. Our experiments showed that the addition of lily powder decreases the viscoelasticity and stability of frozen dough. The absorption rate of the frozen dough was 63.1±0.2% for the control sample, and 66.1±0.1% and 70.9±0.2% for the normally pulverized samples containing 3% and 5% of lily powder, respectively, whereas the absorption rate of the finely pulverized samples tended to increase slightly. The gelatinization results of the frozen dough decreased with the addition of lily powder in terms of the final viscosity, break down, and setback values. Compared to the control sample, the specific volume of the bread products that underwent normal pulverization (5% additive) increased slightly and decreased for the lily bulbs that were finely pulverized (3% additive). The addition of lily powder did not significantly affect the water activity during the storage period of up to 5 days. The hardness of white pan bread increased from 1,948±114.3 to 2,518±154.7 g/㎠ on the first day of storage to 2,571±160.9 to 3,265±147.4 g/㎠ on the 5th day of storage. The hardness was the highest for the 5% sample that underwent normal pulverization, and the samples differed significantly. The longer the storage period, the lower the springness value of the white pan bread became, and this result was most notable for the finely pulverized powder sample. The springness of white pan bread decreased as the amount of lily powder additive and the storage period increased. The sensory test results were excellent in that the appearance, texture, flavor, taste, and overall preference for white pan bread to which 3% of normally crushed lily powder had been added had improved relative to the control sample.

Identification of the Failure of VFD Heat Sink at Fossil Power Plant

Jine Sung Jung,Han Sang Lee,Min Tae Kim,Eui Hyun Kim 한국부식학회 2009 Corrosion Science and Technology Vol.8 No.4

White Pan Bread Dough Characteristics of Anzunbaengi (Triticum aestivum) Whole Wheat Flour Added Herbs

Jung Hyun Gi,Joung Yong Myeon,No Il Hong,Choi Jine Shang 경상대학교 농업생명과학연구원 2019 농업생명과학연구 Vol.53 No.4

In the Anzunbaengi (Triticum aestivum) whole wheat flour mixture group, some herbs (A [white], B [yellow], C [black], D [blue], and E [red]) were added. The physicochemical properties were compared to the strong flour and whole wheat flour mixture groups. The dry gluten content of the control group (strong flour) was 13.5±0.4%, and the content in the whole wheat flour test group was slightly lower in value than the control group. The final viscosity, breakdown, and setback values of the dough were 248.4±0.8, 104.8±0.9, and 103.1±2.9 RVU, respectively. The breakdown was significantly different in the control and whole wheat flour groups. The setback value of the dough was increased by 30 RVU in the whole wheat flour test group compared to the control group by 103.1±2.9 RVU, but there was no significant difference between the test group samples. The consistency of the control dough was 500±10 FU, and the whole wheat flour test group was significantly increased to 585±10~599±10 FU, respectively. The absorption rate was about 2% higher in the whole flour test group than in the control group (66.2±0.3%). The pH of the control paste gradually decreased with fermentation time, and the results of whole wheat flour test group were similar (5.78±0.12~5.88±0.12). As the fermentation time increased, the volume of dough was increased and the result was slightly lower in the whole wheat flour test group than in the control group.

구간적 3차 보간 다항식에 의한 곡면구성에 관하여

김하진(Ha Jine Kim),김민구(Min Koo Kim),윤경현(Kyung Hyun Yoon) 한국정보과학회 1983 정보과학회논문지 Vol.10 No.3

This note is a study on the construction of surfaces by some piecewise cubic interpolating polynomials To derive the two-variables basis functions for surface construction, we form a tensor product of one-variable basis functions which was specified in[3]. And for the coefficients matrix of bicubic B-spline, we take the block Gaussian elimination method. As an numerical example, we introduce f(x,y)= cosx²y and analyze the theoretical, numerical error and verify it with Tektronix 4051 Graphic System. 본 논문은 구간적 3차 보간 다항식에 의한 곡면 구성에 관한 연구이다. 곡면 구성을 위한 2변수 기본 기함수들은 [3]에서 연구된 바 있는 1변수 기본 기 함수들의 tensor 곱으로 만들었으며, bicubic B-spline 의 coefficients matrix는 block Gaussian elimination 방법을 사용하였다. 수치 예로는 f(x,y)=cos ײ y 에 대한 이론적 · 수치적 오차 해석을 검토하고 그 결과를 Tektronix 4051 Graphic System 으로 확인하였다.

Hesperidin과 Hesperetin의 간 손상 동물모델에서 산화적 스트레스에 대한 간 보호 효과

김지현(Ji Hyun Kim),이여(Li Li),김미숙(Mi Suk Kim),조은주(Eun Ju Cho),김현영(Hyun Young Kim),최진상(Jine Shang Choi) 한방비만학회 2022 한방비만학회지 Vol.22 No.1

Objectives: To investigate the protective effect of hesperidin and hesperetin against oxidative stress in 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH)-induced liver toxicity in rats. Methods: Hesperidin or hesperetin (200 mg/kg/day, respectively) was orally administered for 7 days once daily in rats. Subsequently, AAPH (50 mg/kg/day) was administered intraperitoneally. Lipid peroxidation, nitric oxide production, catalase activity, and protein expressions of nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase (iNOS) in the liver tissues were measured. Results: Administration of hesperidin and hesperetin significantly decreased serum aspartate transaminase and alanine transaminase levels in AAPH-induced oxidative stress liver tissues compared with control group. Lipid peroxidation and nitric oxide (NO) production were also significantly reduced by hesperidin and hesperetin in AAPH-induced oxidative stress liver tissues. In particular, lipid peroxidation levels of hesperetin-administered group significantly decreased to 5.02 nmole/mg protein in oxidative stress rats. Hesperidin and hesperetin significantly increased antioxidant activity, such as that of catalase. Furthermore, administration of hesperidin and hesperetin substantially down-regulated the expression of NF-κB and iNOS in liver tissues. Administration of hesperidin reduced NO levels and iNOS expression more than in the hesperetin-administered group. Conclusions: Administration of hesperidin and hesperetin led to a reduction in AAPH-induced liver toxicity by regulating oxidative stress.

국내 산업제어시스템 평가 도구 도입을 위한 CSET 적용 방안 검토

이현영(Lee Hyun Young),신명진(Shin Myung Jine),박태준(Park Tae June) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2

구간적 3차 보간 다항식에 관하여

김하진(Ha Jine Kim),이경환(Kyung Hwan Lee),윤경현(Kyung Hyun Yoon) 한국정보과학회 1983 정보과학회논문지 Vol.10 No.1

Among the basis function for data fitting, m this note, we study on the characteristics of piece. wise cubic Lagrnage, piecewise cubic Hermite and cubic B-spline interpolating polynomials. From the some numerical examples, we analyze the theoretical error of each polynomial and verify it with Tektronix 4015 Graphic system. 본 논문에서는 data fitting 을 위한 basis function 중 piecewise cubic Lagrange, piecewise cubic Hermite 와 cubic B-Spline 에 대한 특성을 연구한 것이다. 이들에 대한 이론적 오차해석을 검토하고 그 결과를 수치적 예를 통해 Tektronix 4051 Graphic System으로 확인하였다.