• 한국초전도ㆍ저온공학회논문지
• /
• 제7권4호
• /
• pp.10-13
• /
• 2005

Transport current and magnetic field which is generated by transport current make AC current - AC mag-netic field condition(AC-AC condition) in AC power application system using HTS tape. Therefore, characteristics of AC loss under the AC-AC condition are necessary to estimate AC loss of power device with accuracy such as HTS transformer. In this paper, we researched transport current loss, magnetization loss by perpendicular magnetic field and total loss which is represented as summation of both losses under the AC-AC condition in single HTS tape. As a result, magnetization loss showed increasing behavior under 65mT and decreasing behavior upper 65mT by influence of transport current. Transport current loss was increased continuously through out whole measurement ranges in the AC-AC condition. Total loss in HTS tape was dominated entirely by magnetization loss.

• Journal of Applied Biological Chemistry
• /
• 제57권4호
• /
• pp.331-336
• /
• 2014

본 연구에서는 최근 산림소득작물로 재배면적이 급증하고 있는 오미자를 대상으로 일반 농경지와 산림농업지에 시비된 식물영양성분의 행방과 유출부하량을 비교 평가하여 환경친화형 산림농업 시스템을 정착하는데 필요한 기초자료를 제공하고자 하였다. 표토 침식 및 식물영양물질의 유출에 더 민감함을 보여주는 지표로 활용되는 유출계수가 일반 농경지 시험구보다 산림농업 시험구에서 더 높게 나타났다. 일반 농경지 시험구와 산림농업 시험구에서 강우-유출에 의한 총질소와 총인의 유출부하량을 평가한 결과, 산림농업 시험구에서 식물영양성분의 손실로 인한 인근 수권 생태계에 끼치는 영향은 미미할 것으로 나타났다. 그러나, 산림농업을 위한 농경지 조성 초기에 식생으로 인한 토양 피복도 부족과 토양구조 불안정으로 인행 상당량의 토사유출이 발생할 수 있는 것으로 나타났다. 따라서, 산림농업을 위한 농경지 조성 초기 단계에는 토양의 유실감수성을 고려한 테라스 및 승수로 등 토양유실 방지대책이 고려되어야 할 것이다.

• Computers and Concrete
• /
• 제33권5호
• /
• pp.573-594
• /
• 2024

This article presents a research study, with both laboratory and field tests, of a deep foundation in a markedly anisotropic medium. Particularly it has focused on the evaluation of the behavior of a pile, one meter in diameter, embedded in a rocky environment with difficult conditions, in the Flysch of the Spanish city of San Sebastián. To carry out the research, the site of a bridge over the Urumea River was chosen, which was supported by pre-excavated reinforced concrete piles. 4 borings were carried out, by the rotation and washing method, with continuous sampling and combined with flexible dilatometer tests. In the field, an Osterberg load test (O-cell) was performed, while in the laboratory, determinations of natural moisture, natural unit weight, uniaxial compressive strength (UCS), point load strength (PLS), compressive wave propagation velocity (V_c) and also triaxial and direct shear tests were carried out. The research results indicate the following: a) the empirical functions that correlate the UCS with the PLS are not always linear; b) for the studied Flysch it is possible to obtain empirical functions that correlate the UCS with the PLS and with the V_c; c) the bearing capacity of the studied Flysch is much greater than if it is evaluated by different load capacity theories; d) it is possible to propose an empirical function that allows evaluating the mobilized shear strength (τ_m), as a function of the UCS and the displacement relative of the pile (δ_r).

• Radiation Oncology Journal
• /
• 제9권1호
• /
• pp.103-109
• /
• 1991

I, II기 intermediate grade악성 임파종에서 방사선 치료의 역할을 극인하기 위하여 서울대학교 병원 치료 방사선과에서 치료받은 162예의 방사선 치료 성적을 분석하였다. 초기의 치료 실패 양상 이 확인 가능한 68 예 중 38.2%는 조사야 내에서 61.8%는 조사야 밖에서 치료 실패 또는 재발 하였다. I기에서는 조사야 내 및 외에서 발생한 치료 실패 양상은 국소 조사야 치료시 각각 30.0%와 70.0%였고, 확대 조사야 치료시는 각각 43.8% 와 56.2%였다. II기에서는 각각 16.7% 와 83.3% 및 41.7%와 58.3%였다. 5년 무병 생존율은 전 환자에서 48.1%였고, I기 및 II기에서 각각 56.3%와 40.4%로 병기에 따른 유의한 차이가 있었다. 10cm 이상의 종괴나 전신적 증상은 무병 생존율에 영향을 미치지 못하였다. 방사선 치료 범위가 큰 경우에 5년 무병 생존율이 양호하였고 특히 I기에서는 유의하였다. 재발후에 시행한 전신 화학요법의 효과를 감안한 5년 생존율은 I, II기에서 각각 65.3% 및 52.2%였으며 병기에 따른 유의한 차이는 없었다. 따라서 5년 무병 생존율을 향상시키기 위해서는 원발 병소와 인접한 임파절 부위를 포함하는 화대 조사야로 치료할 필요가 있으며 재발된 경우에는 전신 화학 요법이 유용할 것으로 시사된다.

• 한국연초학회지
• /
• 제6권2호
• /
• pp.179-184
• /
• 1984

This experiment was carried out to select the suitable burley varieties for paddy field. Two varieties, two $F_1$ hybrids and three $F_1$ hybrids with pale yellow line which were all early maturing were tested in the paddy field condition. The results were as follows. 1. Va 528 and all $F_1$ hybrids flowered 4-8 days earlier than Burley 21. 2. Leaf maturity among varieties and $F_1$ hybrids were not significantly different at first priming, but significant differences were detected from second to forth primings. (MS Ky 12x JB 7802-30)Fl and (MS Br 21 x L8)$F_1$ hybrids matured 3-5 days earlier than Burley 21. Pale yellow hyorids matured early, yielded high and were favorable in physical properties, but were low in quality. 4. Va 528 and (MS Br 21 x L8) $F_1$ hybrid showed earthy maturing, high yield and good quality compared with Burley 21. So two varieties were considered suitable for paddy field cultivation.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1022-1025
• /
• 2003

Although the globe is the most typical valve to control high pressure drop in piping system, it is very hard to figure out the characteristics of flow field in the globe valve caused by its complex geometry. So there is very few studies to find out flow characteristics of globe valve. In this study, numerical analysis for flow field in the globe valve is carried out using the Fluent code which is commercial CFD program. Pressure drop through the globe valve is also measured to verify the results come from numerical analysis. Comparing experiment with numerical analysis, two results are very close to each other. Also finite element method is employed to evaluate the safety of globe valve using the results coming from the flow analysis to make the boundary conditions for FEM analysis. Maximum stress appears on the inlet channel of valve where inlet flow runs against. Because the maximum stress between 11.7 MPa to 3.6 MPa is within 3.4% of yield stress. the structural safety of valve is considered to be very sound

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.1979-1983
• /
• 2011

FRP(Fiber Reinforced Plastic) support insulators for DC(direct current) were developed and their electrical and mechanical characteristics were investigated. Electrical tests were carried out to measure flashover voltages under common use frequency condition. Tensile and bending tests were performed for the mechanical characteristics. The test results showed that FRP support insulators have superior voltage resistances and strengths to porcelain insulators. Field test also is carried out to measure adaptation and to compensate the defect. The test result showed that a new product has no defect in electrical and mechanical.

• 한국동물위생학회지
• /
• 제19권1호
• /
• pp.39-45
• /
• 1996

Sulfonamides are widely used to treat mastitis of cattle in field. The study was carried out to analyze sulfonamid residues In raw milk from south Kyeonggi area. The milk sample was deproteinated with acetone and defatted with hexane. The residual sulfonamides were extracted with ethylacetate, concentrated under vaccum, reconstituted with the acetate buffer-methanol mixture, reacted with fluorescamine, and then analyzed by HPLC-fluorescence detector(EX. 39nm, Em. 495nm) with methanol : acetate buffer system(3/2, v /v) as a mobile phase. The results analyzed by Thin layer chromatography and High performance liquid chromatography were summarized as follows. 1. A total of 24 cases out of 478 raw milk samples(5.0%) collected during April and May showed positive reaction to sulfonamide residues. Among 24 positive reactors, 9 cases were positive to sulfanilamides(32.1%), 8 cases were positive to sulfathiazoles(28.6%) and 5 cases were positive to sulfamonomthoxines (7.9%) , respectively. 2. During July and August, 31 cases out of 464 raw milk samples(6.7%) showed positive re action to sulfonamide residues. Among them S cases were positive to sulfanilamides, 5 cases sulfathiazoles and 5 cases sulfamonomethoxines(16.1%), respectively.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
• /
• pp.171-174
• /
• 2006

When two particles close to each other are in electrophoretic motion, each particle is under the influence of the non-uniform electric field generated by the other particle. Two particles may attract or repel each other due to the dielectric force depending on their positions in the non-uniform electric field. It is shown analytically that two adjusting rigid particles can form an aggregate due to the dielectric interaction. To verify the validity of the theoretical prediction, an experiment is carried out by using a microchannel. In the experiment, AC electric field is used to eliminate cumbersome electroosmotic flow. The experimental result shows that the particles form a chain-like structure, which is typically observed in electro-rheological fluid, due to the dielectric interaction.

• Journal of applied mathematics & informatics
• /
• 제10권1_2호
• /
• pp.175-191
• /
• 2002

The equations of a polar fluid of hydromagnetic fluctuating through a porous medium axe cast into matrix form using the state space and Laplace transform techniques the resulting formulation is applied to a variety of problems. The solution to a problem of an electrically conducting polar fluid in the presence of a transverse magnetic field and to a problem for the flow between two parallel fixed plates is obtained. The inversion of the Laplace transforms is carried out using a numerical approach. Numerical results for the velocity, angular velocity distribution and the induced magnetic field are given and illustrated graphically for each problems.