• 제목/요약/키워드: Magnetic orbital

검색결과 124건 처리시간 0.023초

THREE-DIMENSIONAL CRYSTALLIZING ${\pi}$-BONDING , ${\pi}$-FAR INFRARED RAYS AND NEW SPACE ENERGY RESOURCE

  • Oh, Hung-Kuk
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1996년도 춘계학술발표회 초록집
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    • pp.73-87
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    • 1996
  • The outer-most electrons of metal atoms and the remining valence electrons of any molecular atoms make three dimensional crystallizing $\pi$-bondings. The electrons on the $\pi$-bonding orbital rotate clockwise or counter-clockwise and they then make electro-magnetic waves between atoms on the orbital because electron move between plus charged ions. The three dimensional crystallizing $\pi$-bonding orbitals are quantum-mechanically modeled by a cyclic Kronig-Penny Model and energy band structures are analyzed with their potential barrier thickness. The waves generated between plus charged ions are the particular $\pi$-far infrared rays, which have dual properties between material and electro-magnetic waves and can be measured not by modern electro-magnetic tester but biosensor such as finger's force tester. Because the $\pi$-rays can be modulated with electro-magnetic waves it can be applied for harmful electro-magnetic wave killers. Because the $\pi$-rays make new three dimensional crystallizing $\pi$-bonding orbitals in the material the food and drink can be transformed into a helpful physical constitutional property for human health. Distinction between crystalline and amorphous metals is possible because very strong crystalline $\pi$-bonding orbitals can not easily be transformed into another. The $\pi$-rays can also be applied for biofunctional diagnostics and therapy. Gravitational field is one of the electro-magnetic fields. And also magnetic field and gravitational force field make charge's movement. ($\times$ = q, : magnetic field, : force field, q: plus charge, : velocity field)

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Orbital Solitary Fibrous Tumor : A Case Report and Diagnostic Clues

  • Ha, Joo-Kyung;Park, Bong-Jin;Kim, Yun-Hwa;Lim, Young-Jin
    • Journal of Korean Neurosurgical Society
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    • 제46권1호
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    • pp.77-80
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    • 2009
  • Orbital solitary fibrous tumor (SFT) is a rare tumor originating from the mesenchyme. We describe the clinical presentations, radiological and operative findings, and pathological features of a patient with orbital SFT. The patient was a 46-year-old female who presented with progressive proptosis advanced for 20 months. On ophthalmological examination, no visual impairment was detected, but left eye was found to be obviously protruded on exophthalmometry. Orbital magnetic resonance imaging showed a 2.5 ${\times}$ 2 ${\times}$ 2 cm, intensely enhanced mass in the left orbit, which compressed the eyeball forward and the optic nerve downward. The patient underwent frontal craniotomy with superior orbitotomy and gross total resection was performed for the tumor. The histopathological diagnosis including immunohistochemistry was a SFT. After the surgery, proptosis was markedly relieved without visual impairment. Although orbital SFT is extremely rare, it should be considered in the differential diagnosis of orbital tumors. Clinical presentations such as painless proptosis and CD34 immunoreactivity play a significant role in differentiating orbital SFT from other spindle-cell neoplasms of the orbit.

제1원리 분자궤도계산법에 의한 초기 spin 조건에 따른 $MnO_2$ 반도체의 전자상태 변화 계산 (Calculation on Electronic State of $MnO_2$ Oxide Semiconductor with other initial spin conditions by First Principle Molecular Orbital Method)

  • 이동윤;김봉서;송재성;김현식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.148-151
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    • 2003
  • The spin density of ${\beta}-MnO_2$ structure was theoretically investigated by $DV-X_{\alpha}$ (the discrete variation $X{\alpha}$) method, which is a sort of the first principle molecular orbital method using Hatre-Fock-Slater approximation. The used cluster model was $[Mn_{14}O_{56}]^{-52}$. The ${\beta}-MnO_2$ is a paramagnetic oxide semiconductor material having the energy band gap of 0.18 eV and an 3 loan-pair electrons in the 3d orbital of an cation. This material exhibits spin-only magnetism and has the magnetic ordering temperature of 94 K. Below this temperature its magnetism appears as antiferromagnetism. The calculations of electronic state showed that if the initial spin condition of input parameters changed, the magnetic state changed from paramagnetic to antiferromagnetic. When d orbital of all Mn atoms in cluster had same initial spin state as only up spin, paramagnetic spin density distribution appeared by the calculation. On the other way, d orbital had alternately changed spin state along special direction the resulted spin distribution showed antiferromagnetism.

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Effects of the Magnetic Part of The Breit Term on Bonding: Model Calculations with Small Diatomic Molecules

  • 류설;;한영규;이윤섭
    • Bulletin of the Korean Chemical Society
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    • 제22권9호
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    • pp.969-974
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    • 2001
  • Model calculations for small molecules Li2, F2, LiF and BF have been performed at the Dirac-Fock level of theory using Dirac-Coulomb and Dirac-Coulomb-Magnetic Hamiltonians with various basis sets. In order to understand what may happen when the relativity becomes significant, the value of c, speed of light, is varied from the true value of 137.036 a.u. to 105 (nonrelativistic case) and also to 50 and 20 a.u. (exaggerated relativistic cases). Qualitative trends are discussed with special emphasis on the effect of the magnetic part of the Breit interaction term. The known relativistic effects on bonding such as the bond length contraction or expansion are demonstrated in this model study. Total energy, $\pi-orbital$ splitting, bond length, bond dissociation energy and dipole moment are calculated, and shown to be modified in a uniform direction by the effect of the magnetic term. Inclusion of the magnetic term raises the total energy, increases the bond length, reduces the $\pi-orbital$ splitting, increases the bond dissociation energy, and mitigates the changes in dipole moment caused by the Dirac term.

SPIN POLARIZED PHOTOEMISSION AND MAGNETIC CIRCULAY DICHROISM STUDY OF FeAl THIN FILMS

  • Kim, K.W.;Kudryavtsev, Y.V.;Chang, G.S.;Whang, C.N.;Lee, Y.P.
    • 한국진공학회지
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    • 제6권S1호
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    • pp.53-58
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    • 1997
  • It is well known that the equiatomic FeAl alloy crystallizes in a paramagnetic CsCl structure and is very stable in a wide temperature range owing to a significant charge transfer from Al to Fe. A presence of structural defects normally enhances the magnetic and magneto-optical properties of this alloy. In this study spin-resolved photoemission and magnetic circular dichroism (MCD) were carried out on both ordered and disordered $Fe_{0.52}Al_{0.48}$ alloy films. The disordered state in the alloy films was obtained by a vapor quenching deposition on cooled substrates. It is shown that the order-disorder transition in the Fe0.52Al0.48 alloy films leads to a significant change in the spin polarization. Form the MCD results the orbital and spin magnetic moments of the constituent atoms are obtained. According to the sum rule the spin and orbital magnetic moments of Fe in the disordered FeAl film are $\mu\frac{SR}{spin}=0.8\mu_B$ and $\mu\frac{SR}{orb}=0.14\mu_B$ respectively. The spin magnetic moment is also evaluated to be $\mu\frac{BR}{spin}=0.77\mu_B$ by the branching ration method employing a photon polarization of 90%.

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자성 연구에 있어서의 핵자기공명의 쓸모 (Application of NMR to Magnet Study)

  • 이순칠
    • 한국자기학회지
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    • 제20권2호
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    • pp.68-74
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    • 2010
  • 핵자기공명은 물질 내부의 국소적인 스핀 환경에 대한 정보를 제공하기 때문에 자성체 연구에 대단히 유용하다. 자성체 내 이온의 원자가 혹은 자기모멘트, 스핀들의 기울어짐각, 오비탈 상태 등을 직접 측정할 수 있게 해주며 자성이온들의 위치나 자구와 자구벽의 변화 등에 대한 정보를 제공한다. 이렇게 정보를 제공할 수 있는 단순화된 원리를 적용사례를 들어 설명한다.

두피하 혈종으로부터 확장된 안구내 골막하 혈종 - 증 례 보 고 - (Subperiosteal Orbital Extension of Subgaleal Hematoma - A Case Report -)

  • 정병하;문재곤;김창현;이호국;황도윤
    • Journal of Korean Neurosurgical Society
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    • 제29권9호
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    • pp.1255-1257
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    • 2000
  • The authors present a case of subperisoteal orbital hematoma which is extended from subgaleal hematoma. A 15-year-old-male was admitted with a complaint of multiple visual symptoms of left eye following blunt head trauma. He has suffered from Wilson's disease. Several coagulative laboratory findings were abnormal(fibrinogen and coaguation factor V, X). Computed tomography, sonography and magnetic resonance imaging established the subperiosteal orbital extension of subgaleal hematoma into the orbital cavity. Needle aspiration of orbital subperiosteal hematoma was failed but symptoms and signs of the patient were much improved spontaneously following decrease of subgaleal hematoma. The literature is reviewed and management is discussed.

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Schwannoma of the Orbit

  • Kim, Kwang Seog;Jung, Jin Woo;Yoon, Kyung Chul;Kwon, Yu Jin;Hwang, Jae Ha;Lee, Sam Yong
    • 대한두개안면성형외과학회지
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    • 제16권2호
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    • pp.67-72
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    • 2015
  • Background: A schwannoma is a benign, slow-growing peripheral nerve sheath tumor that originates from Schwann cells. Orbital schwannomas are rare, accounting for only 1% of all orbital neoplasms. In this study, we retrospectively review orbital schwannomas and characterize clinical, radiologic, and histologic features of this rare entity. Methods: A retrospective review was performed to identify patients with histologically confirmed orbital schwannoma, among a list of 437 patients who had visited our hospital with soft tissue masses within the orbit as the primary presentation between 2010 and 2014. Patient charts and medical records were reviewed for demographic information, relevant medical and family history, physical examination findings relating to ocular and extraocular sensorimotor function, operative details, postoperative complications, pathologic report, and recurrence. Results: Five patients (5/437, 1.1%) were identified as having histologically confirmed orbital schwannoma and underwent complete excision. Both computed tomography (CT) and magnetic resonance imaging (MRI) studies were not consistent in predicting histologic diagnosis. There were no complications, and none of the patients experienced significant scar formation. In two cases, patients exhibited a mild postoperative numbness of the forehead, but the patients demonstrated full recovery of sensation within 3 months after the operation. None of the five patients have experienced recurrence. Conclusion: Orbital schwannomas are relatively rare tumors. Preoperative diagnosis is difficult because of its variable presentation and location. Appropriate early assessment of orbital tumors by CT or MRI and prompt management is warranted to prevent the development of severe complications. Therefore, orbital schwannomas should be considered in the differential diagnosis of slow-growing orbital masses.

Magnetic Properties of Transition Metal Monolayers on Ta(001) Surfaces

  • Youn, S.J.;Hong, S.C.
    • Journal of Magnetics
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    • 제13권4호
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    • pp.140-143
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    • 2008
  • The magnetic and structural properties of transition metal (Mn, Fe, Co) monolayers on Ta(001) surfaces are investigated theoretically by using the first principles full-potential linearized augmented plane wave method. Mn and Fe monolayers become ferromagnetic on Ta(001) surfaces while Co monolayers becomes non-magnetic. The paramagnetism of Co monolayers is explained by the Stoner theory of magnetism. The magnetic coupling of a transition metal overlayer with a substrate is ascribed to the orbital hybridization between the s and d orbitals of the transition metal.

A Practical Method to Correct the Saturation Effect in XMCD Spectra

  • Kim, J.Y.
    • Journal of Magnetics
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    • 제13권3호
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    • pp.85-87
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    • 2008
  • I report a simple method to correct the saturation effect in absorption spectra measured in total electron yield (TEY) mode. It does not require additional measurements of the X-ray penetration depth. In order to check the reliability of the method, X-ray magnetic circular dichroism (XMCD) spectra for polycrystalline Fe were measured at two different incident angles, and then processed with the method. The two resultant XMCD spectra were identical, and their sum rule analysis produced the ratios of orbital magnetic moment to spin magnetic moment, which were very close to the well-known value.