Correlation Between Primary Si and Silicide Refinement Induced by Ultrasonic Treatment of Multicomponent Al–Si Alloy Containing Ti, Zr, V, and P

Jae‑Gil Jung,Young‑Hee Cho,Tae‑Young Ahn,Jae‑Hee Yoon,Sang‑Hwa Lee,Jung‑Moo Lee 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

The correlation between primary Si and silicide refinement induced by ultrasonic treatment (UST) of multicomponent Al–Sialloy containing Ti, Zr, V, and P was investigated. UST significantly refined the primary Si phase owing to cavitation-inducedwetting and deagglomeration of MgAl2O4particles. Lowering the UST finish temperature caused deterioration of the degreeof primary Si refinement, instead leading to silicide refinement. Cavitation-induced silicide nucleation on wetted MgAl2O4consumed the MgAl2O4particles, particularly in the case of primary Si nucleation. Similarly, the formation of an AlP phaseon the silicide phase reduced the nucleation efficiency of the AlP phase. Poisoning of the MgAl2O4and AlP phases by thesilicide phase was responsible for the deterioration in primary Si refinement. Room-temperature tensile strength and hightemperatureelongation were increased by UST and were dependent on the size of primary Si.

자본시장의 완전개방과 그에 따른 당면문제

윤재희 안양대학교 1997 논문집 Vol.17 No.-

Korean government has gradually opened capital market against foreign countres. However, Korea' economy has recently confronted with serious crisis on holding foreign exchanges. Due to this problem the government eventually decided to open capital market perfectly. In this regard, first of all, this study shows the relation between free capital market and the exchange rate variability, and how exchange rate variability affects the export industries. Secondly, this study tells us how the institutional investors can solve its problems facing with free capital market. To deal with the second subject is specially important to get out of current economic difficultly, so called IMF period, because stock market depends highly on the behavior of the institutional investors. To analyze above two subjects, this atudy, firstly, describes the history of Korea's exchange rate system to predict its future. Secondly, basic conditions for the free capital market are analyzed. Thirdly, how the exchange rate variability affect the expoting sector is explained by using microeconomic analysis. Finally, the problems of institutional investors facing with the free capital market are analyzed.

분리 대두단백의 소화율과 전기영동패턴에 미치는 Phytate의 영향

윤재영,조희경,이서래 이화여자대학교 생명과학연구소 1993 생명과학연구논문집 Vol.4 No.-

Phytate 함량이 다른 두 분리 대두단백(HSPI; high-phytate soy protein isolate, LSPI; low-phytate soy protein isolate)을 제조하여 pH 및 phytate 첨가량이 그들의 용해도와 소화율에 미치는 영향을 알아보았고 분리 대두단백을 용해도에 따라 분별한 후 그들의 특성을 전기영동을 통하여 알아보았다. LSPI와 HSPI 모두 분자량이 13.6~81.1 kDa 에 이르는 단백질 성분으로 이루어져 있으며 산성 pH에서 18.0~35.0 kDa의 단백질은 phytate와 잘 결합하지 않는 특성을 가졌다. LSPI를 용해도에 따라 분별하였을 때 gliadin을 구성하는 단백질은 pH2에서 phytate와 쉽게 결합하지 않았다. 대두 단백질은 pepsin 소화율은 phytate 첨가량이 증가할수록 크게 저하되었다. This study was carried out to examine the effects of phytate addition on the solubility and digestibility of the low-phytate soy protein isolate (LSPI) and high-phytate soy protein isolate (HSPI). In SDS-polyacrylamide gel electrophoresis of soy protein isolate, different patterns of proteins were observed in both HSPI and LSPI at various phytate and pH levels, suggesting that phytate may bind specifically to certain protein fractions at a particular pH. For example, proteins of M.W. 1.8~3.5kDa resisted phytate binding at acidic pH. LSPI was fractionated into albumin, globulin, gliadin and glutelin; and phytate was shown to bind with difficultly to all three gliadin bands. Effects of phytate on the pepsin digestibility of soy proteins were apparent, especially in the short term digestion.

Porphyromonas endodontalis 의 Lipopolysaccharide가 섬유아세포의 세포막 투과성에 미치는 영향

윤수한,김민겸,김재희 大韓齒科保存學會 1999 Restorative Dentistry & Endodontics Vol.24 No.3

천해역에서 장파의 변형에 대한 실험적 연구

윤영호,조재희 도립 강원전문대학 2000 道立 江原專門大學 論文集 Vol.3 No.-

The propagations of surface wave in the region with depth discontinuity caused by dredging for navigation channel, and reclamation etc. induce the soil troubles such as moorage's siltation and beach erosion. In this paper, at first experiments were conducted to investigate the wave deformation over rectangular pit. The effects of many parameters such as the depth ratio, shape ratio of pit, wave steepness and period on the wave deformation near the pit are investigated. Secondly, numerical analysis is performed. Wave field is divided into two regions which are the interior and the exterior region of the pit, respectively. The governing equations for the long waves over the pit are integrated. Application of Green's second identity using the appropriate Green functions in each region leads to a pair of integral equation for the potential and it's normal derivative as unknown variables in each region. The numerical experiments are conducted by solving above integral equations using the boundary element method. Finally, The measured values are compared with the computed ones. The results show that the computed values are underestimated a little, however, two values are relatively good agreements.

Carotid Siphon 질환의 경안와 초음파와 자기공명 혈관조영술의 진단적 가치

배희준,윤병우,노재규 대한신경과학회 1999 대한신경과학회지 Vol.17 No.1

환율변동성이 한국수출에 미치는 영향

윤재희 안양대학교 사회과학연구소 1995 社會科學硏究 Vol.3 No.-

Abstract The adoption of the floating exchange rate system in 1980 has generated considerable interest about the question of exchange rate volatility and its impact on the level of export of Korea. The purpose of this study is to investigate empirically the effects of exchange rate risk on the export performance of Korea. As expected, in most cases, the bilateral exchange rate volatilities of floating exchange rate regime are greater than those of pegged exchange rate regime. Aggregate estimation of an export supply function shows that exchange rate volatility is negatively related to exports and that the change in exchange rate regime is associated with a structural shift in the export equation. Bilateral estimation results show that most countries have positive and significant signs for the coefficients of foreign income, price level, and exchange rates. The only negative impact is the volatility of exchange rate. This tells us that the volatility of exchange rate can be a significant factor in exports of Korea. This also implies that the exchange rate policy of Korea should be carried out for the stability.

한국의 외환위기 원인과 대책에 관한 연구

윤재희 안양대학교 사회과학연구소 1998 社會科學硏究 Vol.6 No.-

ABSTRACT Korea's economy has experienced so called 'IMF period' for about one year. For this period many people have tried to find the exact causes why Korea's economy was faced with IMF period from the end of 1997. However, there were still no clear and arranged answers for the question. Therefore this study first shows the exact causes for the foreign exchange risk. Because exact analysis of the cause might be helpful for the solutions or counterpanes. Secondly, on the basis of the exact causes, this study suggests various counterpanes for the IMF period.

한국의 경제교육에 대한 고찰

윤재희 안양대학교 복지행정연구소 1998 福祉行政硏究 Vol.14 No.-

우리는 일상생활에서 지속적으로 다양한 경우의 경제문제에 직면하게 되기 때문에 어떠한 형태로든 의사결정을 내려야 한다. 그런데 합리적인 의사결정을 내릴수 있는 능력은 타고날 때부터 갖고 있는 것이 아니기 때문에 이에 합리적으로 대처할 수 있으려면 경제의 기본 개념 및 원리에 대한 이해가 필요하고, 이는 교육과 훈련을 통해서만 터득될 수 있다. 따라서 정부와 사회는 올바른 경제교육을 위해서 항상 노력을 해야 한다. 교육은 한 나라의 국민을 어떠한 방향으로 이끌어 가느냐 하는 나라의 장래를 결정해 주기 때문이다. 본 논문은 우선 경제교육의 실태와 문제점을 학교경제교육과 사회경제교육으로 나누어서 분석해 보았고, 둘째로 현재 IMF 경제위기의 원인 중의 하나는 과소비라는 측면에서, 미래의 주 소비자가 될 청소년을 대상으로 한 청소년소비자교육에 초점을 맞추어서 그 실태를 파악했다. 셋째로 미국과 일본의 대 국민경제교육의 현황을 파악해 봄으로써 우리와의 차이를 알아봄과 아울러 이들의 시사점이 무엇인가를 파악해 보았다.

Lymphangioma에 의한 거설증을 지닌 환자의 개교합 증례보고 : A CASE REPORT

윤희훈,이상대,김영재,장기택,한세현,이상훈 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.2

Lymphangioma는 림프관에 나타나는 양성종양으로 림프관의 증식을 특징으로 한다. 이 종양의 대부분은 출생 시에 나타나며 종양의 95%정도가 10세 이전에 나타난다. 구강 내에 발생하는 경우에는 혀에서 가장 호발하며 거설증을 야기한다. 대개 양측성으로 혀의 전방 2/3부위에 나타나며 불규칙한 회색과 핑크빛을 띤 소절형태를 보인다. 본 증례 모두에서 환아들은 출생당시 혀에 lymphangioma를 지니고 태어나 거설증을 보였으며 이로 인해 개교합과 하악과성장 양상을 나타내었다. Lymphangioma에 의한 비정상적인 혀의 비대에 의해 환아의 구강과 두개안면부의 주위조직에 대한 적응 결과로 나타난 소견을 관찰하고 관련문헌을 고찰하여 다소의 지견을 얻었기에 보고하는 바이다. Lymphangioma is a benign tumor of lymphatic vessels. The majority of cases are present at birth and 95% of the tumors aroused before the age of 10 years. Oral lymphangioma may occur at various sites but are most frequent on the anterior two thirds of the tongue, where they often result in macroglossia. The lesions present nodularity with gray and pink projections. In the present cases, all the patients who had the macroglossia combined with lymphangioma showed openbite and mandibular prognathism. The purpose of this paper was to report the dental and craniofacial findings of macroglossia combined with lymphangioma and review the pertinent literature through the cases.