• Journal of Magnetics
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• 제10권3호
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• pp.77-79
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• 2005

In this work, we present a comprehensive and systematic approach for the derivation of the dc voltage generated by a magnetic multilayer undergoing ferromagnetic resonance, originally derived by Berger. Our alternative derivation applies especially in the limit of the spin diffusion length much longer than the carrier mean free path.

• Investigative Magnetic Resonance Imaging
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• 제25권3호
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• pp.193-196
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• 2021

Congenital absence of the bilateral internal carotid arteries (ICA) is a very rare occurrence. Recognition of this rare anomaly is important, when considering intracranial endovascular interventions in the event of thromboembolic events with revascularization, transsphenoidal surgery, and the surveillance and detection of associated cerebral aneurysms. We report a case of a 25-year-old man who presented with headache since 2 years ago, and was incidentally discovered to have a congenital bilateral absence of ICAs.

• Investigative Magnetic Resonance Imaging
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• 제26권1호
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• pp.71-75
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• 2022

Tuberculous epididymo-orchitis, a rare form of extrapulmonary tuberculosis, results from hematogenous dissemination or retrograde extension from the lower urinary tract. Herein, we studied the case of a 22-year-old male patient who presented with refractory left scrotal pain and inflammation. The patient also complained of multifocal pain involving the right buttock, posterior thigh, and right wrist, without trauma history. The patient was diagnosed with multifocal tuberculosis by sputum AFB study and right sacroiliac joint biopsy.

• Nuclear Engineering and Technology
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• 제5권1호
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• pp.38-43
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• 1973

A $X_4$형분자인 C $H_4$, Si $H_4$, Ge $H_4$, C $F_4$, Si $F_4$ 및 Ge $F_4$의 양자 또는 불소원자핵의 spin과 분자의 회전사이의 상호작용의 크기를 나타내는 spin-rotation constant $c_{av}$ 를 분자선자기공명방법에 의하여 실험적으로 결정하였다. 강자장근사에 의한 Hamiltonian 은 W $m_{I}$ $m_{J}$=- $g_{I}$ $m_{I}$H- $g_{J}$ $m_{J}$H- $C_{av}$ $m_{I}$ $m_{J}$로 주어지며, $c_{av}$ 는 C tensor의 trace의 3분지 1이 된다. 원자핵자기공오곡선은 v=- $g_{I}$H- $c_{av}$ $m_{J}$로 주어지는 여러개의 회전광공오선의 중첩으로 이룩되며, 전체곡선은 Gauss곡선으로 근사하여 $c_{av}$ 값을 구하였다. 회전공오선은 v= $g_{J}$H- $C_{av}$ $m_{I}$로 주어지며, $m_{I}$는 0, $\pm$1, $\pm$2의 값을 갖는다. $c_{av}$ 의 크기는 인접하는 두 회전공오곡선사이의 진동수치로서도 구할수 있다. 본실험에서 원자핵공오과 회전공오 공히 이용되였다. $c_{av}$ 의 부호는 분자선자기공오실험에서 쓰이는 방법으로서, 양자화되여서 불균일자장에서 분리된 분자선을 진행하는 방향의 좌측 또는 우측에서 부분적으로 차단하면서, 공오곡선의 변화를 보는것으로, 결정된 부호 와 $c_{av}$ 의 크기는 다음과 같다. C $H_4$; -10.3$\pm$0.4kHz Si $H_4$; +3.71$\pm$0.08kHz / Ge $H_4$; +3.79$\pm$0.13kHz C $F_4$; -6.81$\pm$0.08kHz / Si $F_4$; -2.46$\pm$0.06kHz Ge $F_4$; -1.84$\pm$0.04kHz

• Investigative Magnetic Resonance Imaging
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• 제24권1호
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• pp.46-50
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• 2020

Radiation-induced lumbosacral plexopathy (RILSP) is an uncommon complication of pelvic radiotherapy that can result in different degrees of sensory and motor deficits. An age 59 female with cervical cancer, who had received combined chemotherapy and radiation therapy two years before, presented with bilaterally symmetric lower-extremity weakness and tingling sensation. The magnetic resonance imaging showed diffuse T2 bright signal intensity and mild enhancement along the bilateral lumbosacral plexus with no space-occupying masses. RILSP was diagnosed after the exclusion of malignant and inflammatory plexopathies.

• International Journal of Fluid Machinery and Systems
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• 제4권3호
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• pp.324-333
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• 2011

Phase resonance in a centrifugal compressor was experimentally observed and simulated with a commercial CFD code. It was found that pressure fluctuation at the volute outlet becomes the maximum when the rotational speed of the modes caused by the rotor-stator interaction agrees with the sound velocity. A simple one-dimensional theory is presented to explain the phase resonance in turbomachinery.

• Journal of Biosystems Engineering
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• 제21권3호
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• pp.336-342
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• 1996

A 4.1MHz$1^H$ Nuclear Magnetic Resonance(NMR) sensor was designed and manufactured to evaluate the internal quality of fruits. The magnet console having 963gauss magnetic field induction was used for the NMR sensor. To optimize and evaluate the NMR sensor, glycerol and sugar-water solutions were used. $^1$H(proton) resonance signals were used to estimate the sugar contents in fruits. Artificial neural network models were developed to predict sugar contents in fruits from the proton resonance signals. The standard errors of prediction(SEP) were 0.565(apple), 0.394(pear) and 0.415(kiwi), respectively. The result implied that it was possible to evaluate apple, pear and kiwi into 3 grades using the NMR sensor.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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• pp.849-852
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• 2011

This paper investigates a method to tackle the resonance problems of the rectangular power-bus structure(PBS) using thin sheets loaded with periodic metal strips. The equivalent surface impedance of the proposed loading is calculated and involved in the expression of the impedance that accounts for in the PBS, in order to improve the resonance behavior of the original structure. The effects of the strips and the immediate surroundings are illustrated by a number of numerical experiments. Also the restrictions of the technique are addressed.

• Wind and Structures
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• 제25권1호
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• pp.39-61
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• 2017

Buffeting induced resonance (BIR) of hangers on long-suspension bridges is briefly reviewed, including mechanism and experimental verification. Taken the Xihoumen suspension bridge as a numerical example, sensitivities of the BIR of hangers to wind properties are investigated, including types of wind spectrum, turbulence intensity, and spacial coherence of wind fluctuations. Numerical simulations indicate that the BIR of hangers occur to both cases of different wind spectra, showing that it is insensitive to types of wind spectrum. On the other hand, it is found that the turbulence intensity affects buffeting of main cables almost in a linear manner, and so it does to the BIR of the hangers; however, the resonance factors, namely the ratio of the response of the hanger to that of the main cable, are little affected by the turbulence intensity. The spacial coherence of the wind fluctuations, although plays an important role on the buffeting responses of the main structure, has no substantial effects on the BIR of the hangers. Finally, replacement of steel strand with CFRP material has been verified as a very effective countermeasure against the BIR of hangers.

• 한국자기공명학회논문지
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• 제21권4호
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• pp.114-118
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• 2017

Here, I report solid state Dynamic Nuclear Polarization (DNP) of $^1H$ nuclear spins at 0.3 T and 4.2 K. The DNP polarizer was developed based on a commercial X-band Electron Spin Resonance (ESR) modified for DNP, in combination with a NMR console and a liquid-Helium cryostat. By detuning magnetic field, DNP spectrum was measured to find the optimal condition. At +3 mT detuned from on-resonance field, $^1H$ NMR signal of 60:40 glycerol/water frozen solution doped with 20 mM perdeuterated-Tempone was amplified 43 times. The $^1H$ spin polarization obtained at 4.2 K is over 3100 times higher than that at 300 K. The width of the DNP spectrum, which is five times broader than ESR spectrum, is inconsistent with solid effect or thermal mixing, and presumably suggests a different DNP mechanism.