Microstructure and High Temperature Oxidation Property of Fe-Cr-B Based Metal/Ceramic Composite Manufactured by Powder Injection Molding Process

Yeun‑Ah Joo,Young‑Kyun Kim,윤태식,Kee‑Ahn Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.2

This study investigated the microstructure and high temperature oxidation property of Fe–Cr–B metal/ceramic compositemanufactured using powder injection molding process. Observations of initial microstructure showed a unique structurewhere α-Fe and (Cr, Fe)2B form a continuous three-dimensional network. High temperature oxidation tests were performedat 900, 1000 and 1100 °C, for 24 h, and the oxidation weight gain according to each temperature condition was 0.13, 0.84and 6.4 mg/cm2, respectively. The oxidation results according to time at 900 and 1000 °C conditions represented paraboliccurves, and at 1100 °C condition formed a rectilinear curve. Observation and phase analysis results of the oxides identifiedCr2O3and SiO2at 900 and 1000 °C. In addition to Cr2O3and SiO2,CrBO3and FeCr2O4formed due to phase decompositionof boride were identified at 1100 °C. Based on the findings above, this study suggested the high temperature oxidationmechanism of Fe–Cr–B metal/ceramic composite manufactured using powder injection molding, and the possibility of itsapplication as a high temperature component material was also discussed.

DAN 코딩 기법과 웨이브렛 소속함수를 사용한 혼돈 시계열 시스템의 퍼지모델링

이연우,유진영,주영훈 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

In this paper, we propose a new method about wavelet-based fuzzy modeling using a DNA coding method. DNA coding techniques is known that expression of knowledge is various than Genetic Algorithm(GA) usually by made optimization technique because done base in structure of biologic DNA and optimization performance is superior. The proposed method make fuzzy system model in wavelet transform and equivalence relation after identification with coefficient of wavelet transform using a DNA coding techniques. Also, can get fuzzy model effectively of nonlinear system using advantage of strong wavelet transform about function that have sudden change. In this paper, in order to demonstrate the superiority of the proposed method compared with GA.

뇌사환자의 갑상선 기능, 전신대사 및 중증도에 관한 연구

이영주,정금희,왕희정,문봉기,한연희,이영석 아주대학교 의과학연구소 1999 아주의학 Vol.4 No.1

Background and Objectives : Brain death may lead to hormonal depletion, metabolic derangement and multiple organ dysfunction. We have carried out present study to examine the effects of brain death on the thyroid function, metabolic indices, and the severity scoring systems. Methods : 13 adults patients admitted for organ donation or brain death evaluation were examined after brain death was confirmed. Thyroid hormones measured were .thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and free thyroxine (FT4). The metabolic indices measured were arterial ketone body ratio (AKBR), lactic acid (LA), and base defiat (BD). as for reference to the severity scoring systems, APACHE Ⅲ and multiple organ failure score (MOFS) were assessed on the day of brain death confirmation. Arterial blood was drawn for all measurements. Results : As for the thyroid function, there were significant decreases in T3 (40.48±20.96 ng/dL) and T4 (3.47±2.15 ㎍/dL), but no significant change in FT4 (0.75±0.31 ng/dL) and TSH (1.12±1.37 uIU/mL) compared to the normal range. Significant decreases in AKBR (0.39±0.31) and BD (-9.46±5.83 m㏖/L), and significant increase in LA (2.57±2.46 m㏖/L) In metabolic indices, were shown, as for severity scoring systems, APACHE Ⅲ score (101.54±19.41) and MOF score (9.11±2.57) indicated a high mortality. There were significant correlation between thyroid hormones (r=0.565 -0.781) but no correlation among other indices. Also, significant inverse correlations were shown between base deficit and lactic acid (r=-0.660), APACHE Ⅲ score (r=-0.726) and MOF score (r=-0.604). The highest correlation was observed between APACHE Ⅲ score and MOF score (r=0.851). Conclusions : As for the thyroid function, significant decrease in T3 and T4, and almost normal range of FT4 and TSH imply the euthyroid sick syndrome. Abnormal finding of the metabolic parameters indicates an inhibition of the aerobic metabolic rate of the body as a whole. And the severity scoring parameters are compatible with high mortality.

산국의 수량과 유효성분에 대한 NPK의 효과

이경동,양민석,정연규,손보균,조주식,이성태,김필주 한국농화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.2

본 연구는 3요소(N-PO_2O_5-K_2O)처리가 산국(Chysanthemum boreale M.)의 수량과 유효성분에 미치는 효과를 조사하여 효과적인 재배시스템을 개발하고자하였다. 처리구는 무처리, NPK(250-160-160), NK(250-0-160), PK(0-160-160kg/ha)의 5처리로 설정하여 산국을 재배한 결과, 건물수량은 NPK처리구가 PK처리구에 비하여 4.0배의 증수가 있었으며, 다른 처리구보다 무기이온의 흡수율, 생육 및 수량에서 NPK처리구가 가장 우수하였다. 식용으로 많이 쓰이는 꽃의 주요 아미노산은 proline, glutamic acid과 aspartic acid이였고, 다른 처리구들에 비하여 NPK처리구가 높은 함량을 보였다. 혈압강하효과가 우수한 cumambrin A는 PK처리구에 비하여 NPK처리구가 6.2배의 증수효과가 있었다. NK처리구는 NP처리구보다 cumambrin A의함량을 높이기 위해서는 인산의 시용보다 칼리의 시용이 더 요구되며, 야외포장에서의 인산과 칼리의 적정 시비량의 설정이 필요하다고 판단된다. To establish the fertilization condition to increase the productivity of Chrysanthemum boreale M. with high quality, the effects of three nutrients (N, P, K) on the yields and the effective components were investigated in the pot scale. NPK was applied by chemical fertilizers with N-P_2O_5-K_2O = 250-160-160 kg/ha as a main treatment, and NP (N-P_2O_5 = 250-160 kg/ha), NK (N-KO = 250-160 kg/ha), and PK (PO_2-KO_5 = 160-160 kg/ha) treatments were settled as comparison. Dry yields of C. boreale M. was increased significantly to 4 fold higher by nitrogen. Nitrogen increased apparently plant growth and inorganic nutrient uptake. In the flower, which is most useful and edible part as a herbal medicine, main amino acids were glutamic acid and aspartic acids, and the total content was increased significantly by three elements of application. In addition, the content of cumambrin A, which is known to have the effect of blood-pressure reduction, was increased source to 6.2 times by nitrogen higher than that in PK treatment. Potassium was more effective in biosyndiesis of cumatnbrin A than phosphorus, but the biological pathway was not clear, still.

유아의 블록놀이를 통한 놀이문화의 연구

이수남,오연주 안양대학교 인문과학연구소 2001 人文科學硏究 Vol.9 No.-

The purpose of this study was interested in the inter-cultural relation of play participants through the block of the young children, and tried to find out the rule of the play in social system and their experiences of the young children. This study inverstigated how the young children solve their problems through the block play, how they communicate, how the symbolic play is developed, and how behavior patterns of children are categorized. The rules were as follows : 1. The symbolic play was developed with the types of block play. 2. The small things - dinosaurs mode, insects mode - were important role to develop the symbolic play of the young children. 3. Children were interested in making stages for symbolic play rather than doing symbolic play. 4. The structure of paper block had not only provided the stage of the symbolic play but also related the structure of story-telling. 5. There were moral rules of children in their play.

식이섬유가 고콜레스테롤혈증 흰쥐의 지질농도에 미치는 영향

김명주,장주연,이미경,박지윤,박은미 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.1

두경부 종양세포주에 대한 Mithramycin A의 세포자멸사 유도성 및Cisplatin 항암작용 증가효과

이강대,손성환,박종욱,김영록,이봉주,김주연 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.1

Background and Objectives : Cisplatin (CP) is a major chemotherapeutic agent for head and neck cancer. However, cancer cells can get drug resistance through recovering the DNA damage by CP. Mithramycin A (MA) can inhibit gene expression of multidrug resistance gene 1, c-myc or h-ras. The goal of this study is to evaluate the therapeutic effect of MA alone and combination of MA and CP on head and neck cancer cell lines. Materials and Methods : Two head and neck cancer cell lines (AMC-HN4, AMC-HN7) were treated with MA. The cellular proliferation, apoptosis and protein expression were measured with XTT assay, FACS analysis, and western blotting, respectively after MA treatment in cell lines. In order to know the combination effect of MA with CP, the cancer cell lines were treated with MA, CP, and MA/CP combination, and cellular proliferation, apoptosis and expression of apoptosis-associated proteins were measured. Results : MA inhibited the proliferation of head and neck cancer cells and induce dapoptosis. Increase of caspase activation, PLC-?1 fragmentation and percent apoptosis by MA treatment was blocked by z-VAD-fms, but not blocked by N-Acetyl Cystein. Combination of MA and CP significantly inhibited cancer cell growth and increased apoptosis compared to MA and CP alone, and it also suppressed the expression of anti-apoptotic proteins such as XIAP and Mcl-1. Conclusions : The present study suggests that MA alone andMA/CP combination chemotherapy could be a potential regiment for the control of the head and neck cancer.

에탄올 중독된 흰쥐의 간조직 중 지질대사에 미치는 셀렌과 메티오닌의 영향

김명주,이미경,장주연,박은미 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.1

산업체 급식소에서 생산직 근로자에게 제공되고 있는 음식의 적정 분량을 제시하기 위해 목포지역 생산직 근로자 240명을 대상으로 섭취량 측정과 설문지를 이용한 만족도 평가를 실시하였다. 조사대상 근로자의 연령은 30∼39세가 57.1%, 학력은 대부분 고졸이었으며, 건강상태는 52.1%가 건강하다고 하였다. 근로자의 좋아하는 식사의 형태는 한식이었고, 식품을 선택할 때 가장 중요하게 생각하는 것은 맛으로 나타났으며, 식사의 가치관은 조사대상 근로자의 37.1%가 공복을 채우는 것이라고 대답해서 생리적 욕구충족에 가치를 둔 비율이 가장 높았다. 산업체 급식소에서 제공된 음식의 섭취량과 섭취율은 밥류 238g(98.4%), 국류 212g(82.7%), 찌개류 230g(77.2%), 볶음류 40g(80.7%), 조림류 60g(83.5%), 무침류 42g(72.3%), 김치류 51g(75.9%), 일품요리류 406g(77.7%), 구이류 51g(72.6), 부침류 48g(48.7%)였다. 섭취량에 대한 만족도 평가 결과, 섭취량에 대해서 두 비교군 거의 모두가 '적은 양'이라고 대답하였다. 섭취량에 대한 만족도 평가를 기초로 음식의 적정량에 대해 밥류 240∼270g, 국류 270g, 찌개류 310g, 볶음류 60g, 조림류 75g, 무침류 76g, 김치류 67g, 일품요리류 470g, 구이류 80g, 부침류 50g으로 제시할 수 있다. The purpose of this study is to set up a appropriate portion by consumed size of food in industry food-service operation. The results were summarized as follows: 51.7% of the subjects were 30 to 39 years old, 83.3% of them had highschool education. They represented that taste of food was the most important point in food intake. Individual consumption sizes for physical workers in the industry foodservice were cooked rices 238g, soups 212g, pot stewes 230g, stir fries 40g, stewes 60g, fresh and boiled salad 42g, kimchies 51g, one course dishies 406g, grills 51g, meunieres 47g. Properly portioned meal sizes for physical workers based on a statistical data showed cooked rices 240∼270g, soups 270g, pot stewes 310g, stir fries 60g, stewes 75g, fresh and boiled salads 76g, kimchies 67g, one course dishies 470g, grills 80g and meunieres 50g in the foodservice industry.

mGA를 이용한 웨이블렛 퍼지 모델링

유진영,이연우,주영훈 국립7개대학공동논문집간행위원회 2002 공업기술연구 Vol.2 No.-

In this paper, we propose a new approach to Wavelet Fuzzy Modeling using messy genetic algorithm(mGA). mGA has more effective and adaptive structure than sGA with respect to using the changeable-length string. We build a fuzzy system model which is equivalent to the wavelet transform after identifying the coefficients of wavelet transform. We can obtain an accurate system model with a small number of coefficients due to the energy compaction property of the wavelet transform. And it means that we can construct a fuzzy system model with a small number of rules. By the conventional fuzzy modeling method, a problem might arise that a function with abrupt changes can hardly be modeled precisely. Hence, we present a solution to this problem by the advantageous property of the wavelet transform. We demonstrate the superiority of our proposed fuzzy system modeling method over the previous results by modeling a highly nonlinear function.

卷柏의 혈액암세포주에서 抗癌作用에 대한 연구

남항우,이성원,이병주,권칠용,문연자,안성훈,우원홍 한국전통의학연구소 2002 한국전통의학지 Vol.12 No.1

The Sellaginella Tarmariscina is widely used in the traditional oriental herbal medicine for its anti-inflammatory, antioxidant effects. The effects of aqueous extracts of Sellaginella Tarmariscina on the viability and induction of apoptotic cell death were investigated in HL-60 cells. The cell viability after treating with extract of Sellaginella Tarmariscina was quantified by MTT assay. The results showed that could inhibit the proliferation of HL-60 cells and caused a 40% inhibition of HL-60 cells at concentrations of 400 ㎍/ml. The cancericidic effect of Sellaginella Tarmariscina was mediated by apoptosis. Thus, HL-60 cells exposed to Sellaginella Tarmariscina displayed the DNA fragmentation ladder and nucleus chromatin condensation characteristic for apoptosis. In conclusion, our results suggest that the extract of Sellaginella Tarmariscina may induce the apoptotic death in HL-60 cells.