• 제목/요약/키워드: external field

검색결과 1,746건 처리시간 0.027초

산소결핍 페롭스카이트 La1/3Sr2/3FeO2.96의 외부 자기장 하에서의 Mössbauer분광학적 연구 ([Mössbauer] Spectroscopic Study of La1/3Sr2/3FeO2.96 under the External Magnetic Field)

  • 윤성현;정종용
    • 한국자기학회지
    • /
    • 제15권2호
    • /
    • pp.81-84
    • /
    • 2005
  • 다결정성 $La_{1/3}Sr_{2/3}FeO_{2.96}$에서의 전하불균형(charge disproportionation, CD) 전이의 근원에 대해 x선 회절법과 외부장 $M\ddot{o}ssbauer$ 분광법을 이용하여 알아보았다. 전이온도 이상에서 외부 자기장에 의한 효과를 알아보기 위해 시료의 온도를 225K로 유지한 상태에서 6 T이하의 외부 자기장을 감마선의 진행방향에 대해 각각 수직과 수평으로 걸어주었다. 외부장이 없을 경우 평균원자가 $Fe^{3.6+}$에 기인하는 상자성 단일 흡수선이 나타났다. 자기장이 감마선의 방향과 평행할 경우, 면적비가 3:0:1:1:0:3인 자기적 Zeeman 스펙트럼이 중앙의 단일선(singlet)에 중첩되어 나타났다. 하지만 자기장이 감마선의 방향에 수직일 경우엔 중앙의 단일선은 사라지고 면적비 3:4:1:1:4:3인 6-선 스펙트럼만 나타나서 큰 이방성을 보였다. 외부장 하에서 단일 흡수선의 존재는 Fe 이온간의 전자의 재빠른 도약 현상으로 설명하였다. 외부장 하에서도 단일흡수선이 존재해, 자기장이 전자의 도약에 의한 전도메커니즘에 큰 영향을 주지 못하는 것으로 나타났다.

원예내장에 관한 문헌적 고찰 (A Literature Study on The Wonyenaejang mechanism)

  • 류현신;노석선
    • 한방안이비인후피부과학회지
    • /
    • 제14권2호
    • /
    • pp.207-223
    • /
    • 2001
  • The Wonyenaejang is equivalent to the (senile)cataract in western medicine. The word cataract is used to describe the natural lens that has turned cloudy. As the natural lens of the eye becomes cloudy, it does not allow light to pass through it. Cataracts usually start as a slight cloudiness that progressively grows more opaque. As the cataract becomes more mature(increasingly opaque and dense), the retina receives less and less light. The light that does reach the retina becomes increasingly blurred and distorted. This causes gradual impairment of vision. If left untreated, cataracts can cause needless blindness. Although there are many kinds of cataracts, a senile cataract is the most common one. We chose the oriental medicine textbooks and the oriental medicine journals that were dealing with the symptoms, etiology, and internal/external treatments. The results were as follows : 1. The main causes of this disease are weak liver and kidney, burning up of the wind and heat in the liver and gall, weak spleen and stomach. 2. As the internal treatment of the Cataract, Geegukjihwangtang is mostly prescribed. 3. As the external treatment of the Cataract, (l) In the field of medicine for external application is commonly prescribed (2) In the field of drug action, frequently used treatments are as follows. emission of the evil, alleviation of fever, removal of lump of blood, and the medicine for external applications. (3) In the field of four Qi, cold medicine is commonly prescribed. (4) In the field of five tastes, bitter/hot/sweet mdicine are commonly prescribed. (5) In the field of toxicity, non-togic medicine is commonly prescribed. (6) In the field of channel distribution, most of the medicine belong to liver channel.

  • PDF

해석적 방법을 이용한 반경방향 영구자석을 갖는 자기 스퍼 기어의 토크특성해석 (Torque Analysis of Magnetic Spur Gear with Radial Magnetized Permanent Magnets based on Analytical Method)

  • 민경철;최장영;성소영;박종원
    • 전기학회논문지
    • /
    • 제64권4호
    • /
    • pp.545-551
    • /
    • 2015
  • This paper deals with torque analysis of magnetic spur gear with radial magnetized permanent magnets based on analytical method. The analysis is implemented in three parts: First, on the basis of magnetic vector potential and a two-dimensional (2D) polar-coordinate system, the magnetic field solution due to permanent magnet of source gear are obtained. And by using derived magnetic field solutions, the analytical solutions for external magnetic field distribution which affects load gear are obtained. Second, by using coordinate conversion, external magnetic field which is on the primary coordinate system is converted to the secondary coordinate system. Finally, the load gear is reduced to equivalent current densities, and the torque is computed on these currents in the external field of the source magnet. These analytical results are validated by comparing with the 2-D finite element analysis (FEA).

Angle Sensors Based on Oblique Giant Magneto Impedance Devices

  • Kim, Do-Hun;Na, Ji-Won;Jeung, Won-Young
    • Journal of Magnetics
    • /
    • 제14권1호
    • /
    • pp.42-46
    • /
    • 2009
  • The measurement of external magnetic field orientation using Giant Magneto Impedance (GMI) sensors has been performed. A soft magnetic alloy of $Co_{30}Fe_{34}Ni_{36}$ was electroplated on a Si wafer with a CoFeNi seed layer. V-shaped microwire patterns were formed using a conventional photolithography process. An external magnetic field was generated by a rectangular AlNiCo permanent magnet. The reference direction was defined as the external magnetic field direction oriented in the middle of 2 GMI devices. As the orientation of the magnetic field deviated from the reference direction, variation in the field component along each device introduced voltage changes. It was found that, by taking the voltage difference between the left and right arms of the Vshaped device, the nonlinearity of each device could be significantly reduced. The fabricated angle sensor had a linear range of approximately $70^{\circ}$ and an overall sensitivity of approximately 10 mV.

외부자장에 의한 초전도체의 전기적 특성 변화 기구 (Effects of Applied Magnetic Field on the Electrical Properties of High Tc Superconductor)

  • 이상헌
    • 한국분말재료학회지
    • /
    • 제13권3호
    • /
    • pp.217-222
    • /
    • 2006
  • The relationship between electrical properties of superconductor and externally applied magnetic field was studied to develop a magnetic field sensor. The electrical resistance of the superconductor was increased by applying external magnetic field and even after removal of the magnetic field. This behavior was related to the magnetic flux trapped in the superconductor, which penetrated through the material by the external magnetic field. Some portion of the superconductor was changed to a normal state by the trapped magnetic flux. The appearance of the normal state yielded to enhance the electrical resistance.

해석적인 방법과 수치적인 방법에 의한 고온초전도테이프의 결합손실 계산 (Calculation of Coupling Loss in a HTS Tape by using Analytic Method and Numerical Method)

  • 심정욱;이희준;차귀수;이지광;한송엽
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
    • /
    • 제48권6호
    • /
    • pp.309-315
    • /
    • 1999
  • Coupling loss is generated by the time-varying external magnetic field in the normal matrix of the multi-filamentary HTS tape. This paper calculates the coupling loss in the HTS tape. Analytic calculation of the coupling loss cannot consider the effect of the different shapes and the arrangement of the filaments. Numerical calculation by using finite element method and analytic calculation of the coupling loss have been done in this paper and results of two calculations have been compared. Transverse magnetic field and longitudinal magnetic field were considered as the external field.

  • PDF

박막 자기저항 소자 제작 및 출력의 인가자장 각도 의존성 (Fabrication of Thin film Magnetoresistive Device and the Dependency of Applied Manetic Field Direction)

  • 민복기;이원재;정순종;송재성
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 초전도 자성체 연구회
    • /
    • pp.50-54
    • /
    • 2003
  • The output characteristics of thin film NiO/NiFe bilayered magnetoresistive device have been measured as a function of the direction of external magnetic field. Each layer was fabricated by rf magnetron sputtering method, and especially, the under layer, NiO, was fabricated under the in-situmagnetic field of about 1000Oe. The magnetoresistive devices were designed with the angle of 45degree between the direction of current of the device pattern and the induces magnetic field in the NiO film layer. The output of the devices had a good linearity when the devices were placed on the external magnetic field perpendicular to induced field direction and also 45 degree with the currenr path direction.

  • PDF

Numerical Calculation of the Deflected Path of Electrons through Water under External Magnetic Fields

  • Jeong, Dong-Hyeok;Kim, Jhin-Kee;Shin, Kyo-Chul;Kim, Ki-Hwan;Kim, Jeung-Kee;Oh, Young-Kee;Ji, Young-Hoo;Lee, Jeong-Ok;Kim, Seung-Kyu
    • 한국의학물리학회:학술대회논문집
    • /
    • 한국의학물리학회 2003년도 제27회 추계학술대회
    • /
    • pp.71-71
    • /
    • 2003
  • The study on magnetic field combined radiation therapy, as a new technique to modify the dose distributions using external magnetic field, has been investigated. The goal of the study is to develop the techniques for dose localization, as a particle beam, from the strong magnetic fields. In this study, in order to study the principle of dose deposition in external fields, as a basic approach, we have calculated approximately the paths of traveling electrons in water under external magnetic fields with numerical methods. The calculations are performed for a primary particle by cumulating the steps which are defined as small path lengths which energy loss can be ignored. In this calculation, the energy loss and direction change for a step was calculated by using total stopping power and Lorentz force equation respectively. We have examined the deflected paths of the electron through water as a function of external magnetic field and incident electron s energy. Since we did not take account of the multiple scattering effects for electrons through water, there are errors in this calculation. However, from the results we can explain the principle of dose variation and dose focusing for electron beams under strong magnetic fields in water.

  • PDF

전자.통신 분야에서 중소기업 규모에 따른 내.외부 혁신활동이 혁신성과에 미치는 영향에 관한 연구 (The Effect of Innovation Activities on Innovation Performance according to the size of SMEs in the Field of Electronics and Communication Industry)

  • 신선아;이문수
    • 산업경영시스템학회지
    • /
    • 제37권1호
    • /
    • pp.79-90
    • /
    • 2014
  • The Purpose of this study is to empirically examine the impact of various internal and external innovation activities of SMEs on their innovation performances in the field of electronics and communication industry. Drawing upon the literature review, internal and external innovation activities are defined and conceptualized, and independent, dependent and moderator variables are developed. We have used survey-based data for this study from the survey of technology innovation activities in manufacturing industry, which was conducted by the Science and Technology Policy Institute (STEPI) in 2010. The main result of this study shows that there were no significant differences in the impact of innovation activities on market performance according to the size of SMEs. On the other hands, we found that there were significant differences in the impact of innovation activities on technological innovation performance according to the size of SMEs. Therefore, in order to make high technological innovation performance, companies in the field of electronics and communication industry need to properly implement the internal and external innovation activities by considering their size.

Spin Torque Nano-Oscillator with an Exchange-Biased Free Rotating Layer

  • You, Chun-Yeol
    • Journal of Magnetics
    • /
    • 제14권4호
    • /
    • pp.168-171
    • /
    • 2009
  • We propose a new type of spin torque nano-oscillator structure with an exchange- biased free rotating layer. The proposed spin torque nano-oscillator consists of a fixed layer and a free rotating layer with an additional anti-ferromagnetic layer, which leads to an exchange bias in the free rotating layer. The spin dynamics of the exchange-biased free rotating layer can be described as an additional exchange field because the exchange bias manifests itself by the existance of a finite exchange bias field. The exchange bias field plays a similar role to that of a finite external field. Hence, microwave generation can be achieved without an external field in the proposed structure.