이온빔 스퍼터링법에 의해 증착된 Ni-Zn 페라이트 박막의 특성연구

학위논문(석사)--서울대학교 대학원 :무기재료공학과,1996.Maste

수직축 조류발전 터빈의 성능에 미치는 설계인자들의 영향 연구

The west and south coastal region of Korea has very strong tidal current speeds and therefore accommodates many suitable sites for the application of Tidal Current Power. This paper deals with effect that design parameter of tidal current vertical axis turbine to performance. For the analysis on VATT(Vertical-Axis Tidal current Turbine), the numerical approach was made by using the commercial CFD software FLUENT 6.3. First at all, they ascertained that characteristic of turbine parameters such as span, turbine diameter, number of blade, shape of blade, tip speed ratio, solidity and current speed. Second, this paper provided that effect of turbine diameter and current speed on the efficiency of VATT. And than, study on the effect of Reynolds number in turbine efficiency quite big especially at low Reynolds number below. Third, the paper deal with any blockages such as duct or flow fence around the turbine. turbine performance has benefit by a blockage effect. Fourth, present paper has proposed optimal solidity for VATT.C o n t e n t s Contents ⅰ Abstract ⅲ Nomenclatures ⅳ List of Tables ⅴ List of Figures ⅵ 제 1 장 서 언 1.1 연구배경 1 1.2 연구 방향 7 1.3 수직축 조류발전 터빈의 특성 8 제 2 장 조류발전 수직축 터빈의 설계변수 정의 2.1 날개수 (Z) 10 2.2 날개 형상 11 2.3 터빈 직경 12 2.4 터빈 블레이드의 길이 (span) 13 2.5 터빈 축 직경 14 2.6 터빈 회전 속도와 조류 속도 15 2.7 끝단속도비(tip speed ratio, λ) 17 제 3 장 조류발전 수직축 터빈의 성능에 미치는 설계인자 3.1. 계산 검증 18 3.1.1 검증 대상 19 3.1.2 검증 결과 20 3.2. 직경, 유속의 영향 검토 21 3.2.1 개요 21 3.2.2 계산조건 22 3.2.3 유속 변화 영향 24 3.2.4 유속 변화 영향 25 3.2.5 결과 검토 26 3.3. 제한 수로의 영향 검토 27 3.3.1 개요 27 3.3.2 계산조건 28 3.3.3 결과 검토 29 3.3.4 정리 32 3.4. 날개 수, 코드 길이 변화의 영향 33 3.4.1 개요 33 3.4.2 계산 조건 34 3.4.3 날개 수 변화 영향 36 3.4.4 코드 변화 영향 37 3.4.5 결과 검토 38 제 4 장 결 론 39 참고문헌 4

Characterization of antihypertensive angiotensin I-converting enzyme inhibitor from Saccharomyces cerevisiae

This study describes the purification and characterization of a novel antihypertensive angiotensin I-converting enzyme (ACE) inhibitory peptide from Saccharomyces cerevisiae. Maximal production of the ACE inhibitor from Saccharomyces cerevisiae was obtained from 24 h of cultivation at 30°C and its ACE inhibitory activity was increased by about 1.5 times after treatment of the cell-free extract with pepsin. After the purification of ACE inhibitory peptides with ultrafiltration, Sephadex G-25 column chromatography, and reverse-phase HPLC, an active fraction with an IC50 of 0.07 mg and 3.5% yield was obtained. The purified peptide was a novel decapeptide, showing very low similarity to other ACE inhibitory peptide sequences, and its amino acid sequence was Tyr-Asp-Gly-Gly-Val-Phe-Arg-Val-Tyr-Thr. The purified inhibitor competitively inhibited ACE and also showed a clear antihypertensive effect in spontaneously hypertensive rats (SHR) at a dosage of 1 mg/kg body weightope

Creating Structure with Pymatgen Package and Application to the First-Principles Calculation

Computational material science as an application of Density Functional Theory (DFT) to the discipline of material science has emerged and applied to the research and development of energy materials and electronic materials such as semiconductor. However, there are a few difficulties, such as generating input files for various types of materials in both the same calculating condition and appropriate parameters, which is essential in comparing results of DFT calculation in the right way. In this tutorial status report, we will introduce how to create crystal structures and to prepare input files automatically for the Vienna Ab initio Simulation Package (VASP) and Gaussian, the most popular DFT calculation programs. We anticipate this tutorial makes DFT calculation easier for the ones who are not experts on DFT programs.