Study on Microstructure and Mechanical Properties of the Al–25Cr–5Si (at%) Alloy Powder Using Gas-Atomization and SPS Process

Yong‑Ho Kim,Hyo‑Sang Yoo,Jeong‑Han Lee,Ik‑Hyun Oh,Hyun‑Kuk Park,Hyeon‑Taek Son 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

In order to investigate the microstructure and mechanical properties on Al–25Cr–5Si (at%) alloy, a mixed powder with pureelements and an alloy powder using a gas atomization process were used. Fine and high purity Al–25Cr–5Si (at%) alloypowder was successfully prepared by gas atomization and densified using a spark plasma sintering (SPS) process. The overallpowder size distribution of the mixed Al, Cr, and Si elemental powders was in the range of 10–15 μm. The atomized Al–Cr–Sialloy powder was fine and spherical in morphology and difficult to be formed by intermetallic formation. Densification wasclearly confirmed at 1000 °C, with almost isolated pores formed, by clear removal of pores between particles, deformationof particles, an increase in the number of contacts, and a change in size between particles. As a result of XRD analysis ofthe sintered compacts, single phase was observed using the mixed powder, but the compact using gas atomization remainedthe alloy phase even at the process temperature. The Vickers hardness of the compacts by mixed powder was observed at59.70 Hv and the compact using gas atomized powders on the temperature 1000 °C of the Vickers hardness increased to702.6 Hv. The compressive yield strength of the compact with mixed powder was 195.24 MPa and the compressive strengthof the compact with gas atomized powder increased to 802.07 MPa. It is considered not to be decomposed by the AlCrSi,Al13Cr4Si4and Al8Cr5phases sintering process, resulting from the improvement of mechanical properties.

식이섬유 보충용 식품의 섭취에 따른 여성의 비만관련 체구성 요인 및 배변만족도의 변화

임용택,강선영,김재등,김성수,김재우,이충영,김정모 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The Purpose of this study was to investigate the effect of functional food including dietary fiber supplementation on body composition concerning obesity and defecation satisfaction of women. Twelve young healthy women but had defecation difficulty were participated as a subject. Body weight, %body fat, WHR mesurement and defecation satisfaction questionnaire were performed before and after 2 weeks' supplementation. The results of this study were as follows : First, Body composition concerning obesity such as body weight(p=.0065), % body fat(p =.0004) and WHR(p=.0007) after 2 weeks' functional food including dietary fiber supplementation was decreased significantly. Second, defecation satisfaction functional food including dietary fiber supplementation was increased significantly(p = .0039). This results suggested that functional food including dietary fiber supplementation should be recommended as effective dietary food for persons with obesity and defecation difficulty.

소아의 상완골 원위부 과간 골절

이우석,정환용,김우식,김용찬,전택수,김남현,김규태 대한골절학회 2004 대한골절학회지 Vol.17 No.4

상완골 원위부 과간 골절은 소아에서는 매우 드물게 발생되는 골절로 대부분 주관절의 굴곡상태로 주관절 후방부에 직접적인 충격에 의해 발생하는 것으로 보고되고 있다. 전위가 없거나 경미한 경우 도수적 정복술 혹은 도수적 정복술 후 경피적 핀고정술을 시행하며, 전위가 심한 골절이거나 도수적 정복술이 불가능한 경우 관혈적 정복술 후 핀고정술을 시행하는 것으로 알려져 있다. 저자들은 전위된 상완골 원위부 과간 골절 환아 2예에서 각각 도수적 정복술과 관혈적 정복술 후 K 강선 고정술을 시행하여 만족한 결과를 얻었기에 보고하는 바이다. Intercondylar fractures of the distal humerus are very rare in children. The pattern of the fracture would suggest that the mechanism of injury involves a fall directly on the flexed elbow. Most agree that the undisplaced fracture can be managed conservatively. With increasing displacement and comminution, the opinions tend to differ. We suggest that closed reduction with percutaneous K wire pinning and open reduction with percutaneous K wire pinning offer a satisfactory methods by which to treat displaced intercondylar fracture in children.

Hybrid Light‐Emitting Diodes: Electrically Driven Quantum Dot/Wire/Well Hybrid Light‐Emitting Diodes (Adv. Mater. 45/2011)

Ko, Young‐,Ho,Kim, Je‐,Hyung,Jin, Li‐,Hua,Ko, Suk‐,Min,Kwon, Bong‐,Joon,Kim, Joosung,Kim, Taek,Cho, Yong‐,Hoon WILEY‐VCH Verlag 2011 ADVANCED MATERIALS Vol.23 No.45

<P>Electrically driven hybrid light‐emitting diodes (LEDs) consisting of quantum dots, wires, and wells based on the nanometer‐sized pyramid GaN structure are reported by Taek Kim, Yong‐Hoon Cho, and co‐workers on page 5364. The LEDs exhibit mixed emissions from InGaN quantum dots, wires, and wells formed at the tops, edges, and sidewalls of the pyramids, respectively. The hybrid LEDs containing low‐dimensional quantum structures provide a broad‐band, highly efficient visible lighting source. </P>

兒童臺의 外部環境觀分析

金龍洙,李鉉澤 COLLEGE OF AGRICULTURE KYUNGPOOK NATIONAL UNIVERSI 1984 慶北大農學誌 Vol.2 No.-

Children's view of outdoor environments was studied by analyzing the drawings of elementary school children. The results obtained were as follows: More area of garden was expressed in drawings of city children than in those of rural children. There was no significant difference between the garden areas in the drawings of male and female children. Housing was expressed overwhelmingly more frequently in the drawings of rural children than in those of city children. Gate and fence were clearly expressed in the drawings of rural children, but not in the drawings of city children. The frequencies of lawn, pond and path as components of garden increased as school year got higher. Whereas flower and flower bed were decreased in frequency and the ratio of flower and flower bed area was decrease to a half in the drawings of sixth year children compared to that of second year children. City children expressed rocks, recreation and sports facilities frequently within their gardens. This obviously reflected the limited play space for city children. In preference of children, pine, ginko, juniper, hymalaya cedar were high in order among the trees, and rose, hibiscus, chrysanthemum, sunflower, goldenbell tree, and tulip were high in order among the flowers.

PECVD법으로 증착된 전자소자용 thiophene 박막의 전기화학적 신뢰성에 관한 연구

김정구,박진택,최윤석,부진효,유용재 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.6

The corrosion failure of electronic devices has been a major reliability concern lately. This failure is an ongoing concern because of miniaturization of integrated circuits(IC) and the increased use of polymers in electronic packaging. In this paper plasma-polymerized thiophene films were considered as a possible candidate for an interlayer dielectric for multilever metallization of ultra large scale integrated (ULSI) semiconductor devices. The protective ability of above films as a function RF power in an 3.5 wt.% NaCl solution was examined by electrochemical methods and contact angle measurement. The protective efficiency of the film increased with increasing RF power, which induced the higher degree of cross-linking and hydrophobicity of the films.

원발성 폐암 환자의 생존율에 관한 보고

김현태,이상무,어수택,박춘식,정성환,허승재,남충희,강창희,김용훈 순천향대학교 1994 논문집 Vol.17 No.4

We analysed 404 patients with primary lung carcinoma who were treated at Soonchunhyang University Hospital from July, 1985 to september, 1993 in order to investigate the survival rate and epidemiolgical properties of primary lung cancer. They were 330 males and 74 females. The most prevalent decade was seventh. In terms of cell type, the squamous cell was 225 patients (55%), and adenocarcinoma, small cell, mixed type was 21%, 19%, 4%, respectively. Among non-small cell lung carcinoma, stage Ⅲa was the most prevalent one(92%). In case of small cell carcinoma, the limited stage was 64%. The 12-, 24-, 36- month survival rate of total patients was 57%, 31%, 22%, respectivley and median sruvival time was 15 months. The 36-month survival rate tended to be longer in non-small cell lung carcinoma than that of small cell lung cancer, but there was no difference between two groups, statistically. In non-small cell carcinoma, The 36-month survival rate and meidan survival time were longer in the stage Ⅰ and Ⅱ than those of Ⅲa, Ⅲb, Ⅳ (80% versus 38%, 22%, 0%, p<0.05). According to involvement of lymph node, the 36-month survival rate was longer in NO and N1 than those of N2, N3 (61.9%, 48.7% versus 17.7%, 17.3%, p<0.05). In small cell carcinoma, The 36-month survival rate and median survival rate were higher and longer in limited stage than those of extensive stage(16.1% and 13 month vs 10% and 8 month, p<0.05). In conclusion, we report here the incidence of primary lung carcinoma and the survival rate of paients with primary lung carcinoma who were treated in Soonchunhyang University Hospital.

인공 건조법에 의한 마른 명태의 품질 개선에 관한 연구 : 2. Some Methods for Hot-air Dehydration of Alaska Pollack 2. 열풍 건조법에 의한 마른 명태 제조

金用根,金敬順,卞在亨,李應昊,梁升澤 釜山水産大學校 1972 釜山水産大學 硏究報告 Vol.12 No.1

북양명태를 원료로서 마른명태를 가공하는 실험을 하여 다음과 같은 결과를 얻었다. 원료를 해동하여 내장을 제거하고, 그대로 29시간 열풍건조하여 마른명태를 가공할 수 있었으며, 제품의 수율은 22% 수분은 18%였다. 또한 원료어를 등갈이한 다음 머리, 내장, 흑막을 제거하고, 염장한 다음 22시간 열풍건조하여 건조시간도 단축할 수 있고, 색택도 좋은 제품을 만들 수 있고, 수율은 약 12%였다. 또한 원료어를 fillet로 처리하여 염장한 다음 열풍건조하므로서 건조시간을 더욱 단축할 수 있었고, 포장 및 조리하기에 편리한 제품을 가공할 수 있었다. 제품의 수율은 어체의 크기에 따라 차이가 있어 10∼22%였다. 그리고 채육기로 육을 채취한 다음 과산화수소를 써서 거품을 일어켜 새로운 형태의 다공성인 박층건제품을 가공할 수 있었고, 이 다공성 박층건제품은 흡수성이 좋아 instatant 식품으로 이용 가능하다는 결론을 얻었다. In this paper, some dehydration methods for frozen Alaska Pollack Theragra chalcogramma were studied. The cabinet type drier was used for the study. Samples were dehydrated for appropriate time at the air temperature of 38 to 40℃ under the air stream of 3m/sec. The frozen samples were defrosted, eviscerated, and hot-air dehydrated for 29 hours. The yield of dehydrated product was about 22% and moisture content was 18%. The brine salted samples which were headed, split and skinned were also hot-air dehydrated under the same conditions. This dehydration process could reduce dehydration time. The yield of dehydrated product was about 12% and moisture content was about 20%. For another method, frozen samples were first defrosted, washed thoroughly to remove dirt, slime and scales, and then beheaded, skinned and filleted. The fillet was dehydrated after brine salting. The yield was 10 to 22% and moisture content was 12%. The tissue of these hot-air dehydrated products such as round, split and fillet were very firm and difficult to reconstitute. In order to obtain dehydrated product of agreeable texture, another dehydration process was examined. Chopped meat was dipped in alkaline solution of 0.4% hydrogen peroxide for 30 minutes and then agitated for 10 minutes. By these treatment the foamy and emulsified minced meat was spread on a nylon net seated on metal tray, drained, and dehydrated. A better result was obtained by this process comparing with other's. This could be explained for the reason that the process resulted in the meat flake porous by which the meat could be rapidly reconstituted. The texture of the porous meat flake was good for a convenience food.

산업폐수처리를 위한 MBR적용과 Membrane 선택에 관한 연구

김기량,이용택 慶熙大學校 材料科學技術硏究所 1999 材料科學技術硏究論集 Vol.12 No.-

The membrane bioreactor(MBR) is a modification of the activated sludge process, were the secondary settling tank is replaced by a membrane and the solids are separated from the effluent stream by means of membrane. In this study, We have done experment of MBR for treatment of high concentration organic industrial wastewater. This experiment used artificial wastewater to avoid changing of water quality which is changed by kinds of inflow wastewaters, Results of experiment. The hydrophilic membrane are more stable in the biomass filtration, and The UF membranes found to be more efficient for MBR application. The removal rate of COD is more than 98% at 2kg/m³day BOD loading. As a results MBR is more effective to endure problems related to activated sludge process.

인공 건조법에 의한 마른 명태의 품질 개선에 관한 연구 : 1. 열풍 건조중의 명태의 핵산 관련 물질 및 유리 아미노산의 변화 1. Changes of Nucleotides and Their Related Compounds and Free Amino Acid Composition of Alaska Pollack during Hot-air Dehydration

金敬三,梁升澤,金用根,韓鳳浩,李應昊 釜山水産大學校 1972 釜山水産大學 硏究報告 Vol.12 No.1

북양산 냉동명태를 원료로서 열풍건조법으로 마른명태를 가공하였을 때, 건조중의 핵산관련물질 및 유리아미노산의 변화를 실험하였다. 원료육중에는 inosine 함량이 가장 많아 건물증량 기준으로 13.5μmole/g였고, 다음으로 함량이 높은 IMP였는데 5.1μmole/g로서 비교적 낮은 값이었다. 열풍건조중 IMP는 급격히 감소하여 잔존량은 14%에 불과하였으며, inosine은 건조중 50%감소하였다. 한편 hypoxanthine는 약 5배 증가하여 건물중량 기준으로 16.9μmole/g 였다. 건조후 3개월간 저장중에는 건조직후와 비교할 때 핵산관련물질의 변화는 거의 없었다. 그리고 원료 명태 육중의 유리아미노산 조성은 taurine이 가장 많아 전 유리아미노산의 40%를 차지하고 alanine, glycine, glutamic acid가 그 다음이고 비교적 함량이 낮은 것은 lysine, serine, histidine이며, 함량이 극히 낮은 것은 valine, aspartic acid, threonine, isoleucine, leucine등이었다. 열풍 건조중 유리아미노산의 질적 변화는 없었으며. 원료육 유리아미노산에 대하여 건조중 유리아미노산양이 20% 증가하였다. In this paper, the changes of nucleotides and their related compounds and free amino acid composition of Alaska Pollack muscle during hot-air dehydration and storage for three months were determined. The results showed that the contents of inosine and IMP in defrosted sample were 13.5 and 5.1 μmole/g respectively on dry base, and followed by hypoxanthine in order. ATP, ADP and AMP was very low in content. IMP and inosine tended to degrade rapidly during hot-air dehydration while hypoxanthine increased about five times. But the quantitative changes of nucleotides and their related compounds in the muscle of hot-air dehydrated Alaska Pollack during storage were not detected. Taurine was abundant in the muscle extracts, showing 40% of the total amino acid content and followed by alanine, glycine and glutamic acid. Lysine, serine and histidine were low in content respectively, and valine, aspartic acid, threonine and leucine were very poor. The qualitative change in the pattern of free amino acid composition of muscle extracts was not observed during hot-air dehydration. The increase of the total free amino acid during hot-air dehydration was approximately 20%.