• Journal of Magnetics
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• 제19권1호
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• pp.68-71
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• 2014

Copper doped Zinc Oxide nanofilms were prepared using a simple and low cost wet chemical method. The microstructures, phase structure, Raman shift and optical absorption spectrum as well as magnetization were investigated for the nanofilms. Room temperature ferromagnetism has been observed for the nanofilms. Structural analyses indicated that the films possess wurtzite structure and there are no segregated clusters of impurity phase appreciating. The results show that the ferromagnetism in Copper doped Zinc Oxide nanofilms is driven either by a carrier or defect-mediated mechanism. The present work provides an evidence for the origin of ferromagnetism on Copper doped Zinc Oxide nanofilms.

• Journal of Chest Surgery
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• 제28권3호
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• pp.237-246
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• 1995

Between March 1989 and December 1994, one-stage repair was performed for correction of the intracardiac malformations associated with aortic coarctation in 34 patients or interrupted aortic arch in 8 patients via median sternotomy. There were 26 male and 16 female patients, and their body weight ranged from 1.8 to 8 kg [mean weight, 4.0 1.4 kg . The age at the operation ranged from 7 days to 18 months [mean age, 3.1 $\pm$ 3.8 months . The repair of aortic coarctation or interrupted aortic arch was performed using extended end-to-end anastomosis in most of the patients [86%, 36/42 , and six patients underwent ductal tissue excision and patch aortoplasty. Intracardiac defects were corrected concomitantly through the right atrium unless the anatomy dictated otherwise. Obstructive outlet septum was resected whenever necessary. There were seven early deaths [16.8 % , and three late deaths with a mean follow-up period of 25 months [range from 1 to 65 months . Three patients were reoperated upon residual subaortic stenosis, stenosis at the RPA origin, and subacute bacterial endocarditis respectively. None showed any significant residual or anastomotic stenosis postoperatively. One stage repair of the aortic coarctation and interrupted aortic arch associated with intracardiac defect leaves no native coarctation shelf tissue or residual hypoplasia in the repaired segment, has low incidence of recurrent or residual stenosis, minimizes reoperation and incisions, and manages arch hypoplasia easily. We concluded that surgical results of one-stage repair for the intracardiac malformation associated with aortic coarctation or interrupted aortic arch are reasonable.

• Journal of Chest Surgery
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• 제34권11호
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• pp.854-857
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• 2001

양대혈관 좌심실기시는 양대혈관이 좌심실에서 기시하는 드문 선천성 심장기형으로 정확하게 진단하기가 어렵다. 환아는 생 후 2개월에 대동맥축착교정술 및 폐동맥교약술을 받았던 3세된 남아로 대동맥하 심실중격결손, 단일관상동맥을 동반한 양대혈관 좌심실기시로 진단되어 심실중격결손의 첩포봉합, 난원공개존의 봉합 폐동맥 교약부 절제, 그리고 폐동맥간을 좌심실에서 분리 후 우심실로 전위시켜 우심실 유출로 재건술을 받았다. 본 술식은 술 후 좋은 혈역학적 특성을 보였고, 자가조직을 사용함으로써 전위된 폐동맥의 성장잠재성과 판막 기능의 보존으로 술 후 폐동맥 폐쇄부전과 관련된 우심실기능부전의 가능성이 줄어드는 장점이 예상되므로 문헌 고찰과 함께 보고한다.

• 한국재료학회지
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• 제15권5호
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• pp.293-300
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• 2005

ZnO:Li epilayers were synthesized on sapphire substrates by the pulesd laser deposition (PLD) after the surface of the ZnO:Li sintered pellet was irradiated by the ArF (193 nm) excimer laser. The growth temperature was fixed at $400^{\circ}C$. The crystalline structure of epilayers was investigated by the photoluminescence (PL) and double crystal X-ray diffraction (DCXD). The carrier density and mobility of epilayers measured by van der Pauw-Hall method are $2.69\times10cm^{-3}$ and $52.137cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of epilayers obtained from the absorption spectra is well described by the Varshni's relation, $E_g(T)=3.5128eV{\cdot}(9.51\times10^{-4}eV/K)T^2/(T+280K)$. After the as-grown ZnO:Li epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO:Li has been investigated by PL at 10 K. The Peaks of native defects of $V_{zn},\;V_o,\;Zn_{int},\;and\;O_{int}$ showned on PL spectrum are classified as a donors or accepters type. We confirm that $ZnO:Li/Al_2O_3$ in vacuum do not form the native defects because ZnO:Li epilayers in vacuum existe in the form of stable bonds.

• Transactions on Electrical and Electronic Materials
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• 제15권4호
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• pp.207-212
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• 2014

Aluminum-doped zinc oxide (AZO) films were deposited on SiOC/Si wafer by an RF-magnetron sputtering system, by varying the deposition parameters of radio frequency power from 50 to 200 W. To assess the correlation of the optical properties between the substrate and AZO thin film, photoluminescence was measured, and the origin of deep level emission of AZO thin films grown on SiOC/Si wafer was studied. AZO formed on SiOC/Si substrates exhibited ultraviolet emission due to exciton recombination, and the visible emission was associated with intrinsic and extrinsic defects. For the AZO thin film deposited on SiOC at low RF-power, the deep level emission near the UV region is attributed to an increase of the variations of defects related to the AZO and SiOC layers. The applied RF-power influenced an energy gap of localized trap state produced from the defects, and the gap increased at low RF power due to the formation of new defects across the AZO layer caused by lattice mismatch of the AZO and SiOC films. The optical properties of AZO films on amorphous SiOC compared with those of AZO film on Si were considerably improved by reducing the roughness of the surface with low surface ionization energy, and by solving the problem of structural mismatch with the AZO film and Si wafer.

• Journal of Korean Neurosurgical Society
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• 제50권6호
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• pp.532-534
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• 2011

Temple trauma that appears initially localized to the skin might possess intracranial complications. Early diagnosis and management of such complications are important, to avoid neurologic sequelae. Non-penetrating head injuries with intracranial hemorrhage caused by a driven bone fragment are extremely rare. A 53-year-old male was referred to our hospital because of intracerebral hemorrhage. He was a mechanic and one day before admission to a local clinic, tip of metallic rod hit his right temple while cutting the rod. Initial brain computed tomography (CT) and magnetic resonance imaging demonstrated scanty subdural hematoma at right temporal lobe and left falx and intracerebral hematoma at both frontal lobes. Facial CT with 3-D reconstruction images showed a small bony defect at the right sphenoid bone's greater wing and a small bone fragment at the left frontal lobe, crossing the falx. We present the unusual case of a temple trauma patient in whom a sphenoid bone fragment migrated from its origin upward, to the contralateral frontal lobe, producing hematoma along its trajectory.

• 한국소음진동공학회논문집
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• 제14권12호
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• pp.1268-1278
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• 2004

Measurement of noise is not only to know the information of acoustic pressure but to assess human response to noise. To find human response to transportation noise through the laboratory study we have to measure and reproduce noise. The method of noise reproduction is largely divided into monaural and binaural techniques. But human fundamentally hears sound through both ears, referred as binaural hearing. Binaural signal is different from monaural signal because it includes more information of physical phenomena like acoustical reflection, diffraction and refraction. Especially head and pinna play an important role in perceiving change of signal origin. So, the amplitude of binaural signal is higher than that of monaural signal and spectrum of both signals is discriminated. Most of assessment and regulation of transportation noise are, however, based on monaural measurement techniques. The quantitative difference between monaural and binaural measurement is investigated in this study. Comparison on several transportation noisesshows defect of information in monaural measurements.

• Journal of Korean Neurosurgical Society
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• 제45권1호
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• pp.43-45
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• 2009

A 75-year-old female presented with subarachnoid hemorrhage. Angiography revealed a partial duplication (fenestration) in the proximal $A_1$ segment and a ruptured aneurysm at the distal end of $A_1$ fenestration. This congenital anomaly accompanying an aneurysm was associated with duplicated ipsilateral middle cerebral artery (MCA). Congenital defect of the arterial wall and hemodynamic factors at the fenestrated $A_1$ are considered to play a significant role in the development of this aneurysm. The present case is peculiar because not only the ruptured $A_1$ aneurysm was related with the anterior and middle cerebral artery duplication but also the location of $A_1$ fenestration and the origin of $A_1$ aneurysm in a fenestration are quite unusual.

• 한국결정성장학회지
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• 제6권2호
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• pp.194-202
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• 1996

고온가압성형된 다결정상 titanium diboride내에 형성된 전위구조를 투과전자현미경으로 분석하였다. Ion beam thinner를 사용하여 제작한 박편시편은 전위구조에 대한 특징을 드러내 보였다. 이들 특징들은 전위들로 배열된 적각결정입계, ledges나 steps들이 결정입계면에 존재하는 고각결정입계 등이다. 결정입계에서의 ledges나 steps들은 전위형성이나 결정입계 근처에서의 crack전파와 같은 결함구조로서 평가되었고, 고각결정입계는 부분적으로 결정입계전위를 포함하고 있는 것으로 관찰되었다. 또한, 시편의 미세구조에 존재하는 전위들의 Burger's vectors를 결정하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.100-101
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• 2008

To obtain the single crystal thin films, $CuGaSe_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $450^{\circ}C$, respectively. After the as-grown $CuGaSe_2$ single crystal thin films was annealed in Cu-, Se-, and Ga-atmospheres, the origin of point defects of $CuGaSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{CU}$, $V_{Se}$, $Cu_{int}$, and $Se_{int}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Cu-atmosphere converted $CuGaSe_2$ single crystal thin films to an optical n-type. Also, we confirmed that Ga in $CuGaSe_2$/GaAs did not form the native defects because Ga in $CuGaSe_2$ single crystal thin films existed in the form of stable bonds.