• 제목/요약/키워드: $^{211}At$

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적외선 영상에서 소형 표적탐지를 위한 Structuring Element 구조에 관한연구 (A Study on the Structuring Element for the Small Target Detection in the IR Image)

  • 김도종;이부환;임종광;구연덕
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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    • pp.211-214
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    • 2002
  • A novel structuring element for the morphological filter is proposed in order to detect a small target at a long distance. The modeling of the structuring element is based on the real data and implemented by parametric model approach. Several synthetic

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펄스 레이저 증착법으로 제작된 Bi2O3-MgO-ZnO-Nb2O5 박막의 제작 및 특성 분석 (Fabrication and Characterization of Bi2O3-MgO-ZnO-Nb2O5 Thin Films by Pulsed Laser Deposition)

  • 배기열;이동욱;;이원재;배윤미;신병철;윤순길
    • 한국전기전자재료학회논문지
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    • 제23권3호
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    • pp.211-215
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    • 2010
  • Pulsed laser deposition is a very efficient technique for fabricating thin films of complex compounds. In the present work, $Bi_2O_3$-MgO-ZnO-$Nb_2O_5$ (BMZN) pyrochlore thin films were deposited on platinized Si substrates at various temperatures by using pulsed laser deposition technique. These films have been characterized by X-ray diffractometer (XRD), atomic force microscopy (AFM) to investigate their structural, morphological properties. MIM structure was manufactured to analyze di-electrical properties of BMZN thin films. XRD results reveal the thin films deposited at less than $400^{\circ}C$ show only amorphous phase, the crystallized thin films was observed when the thin films were prepared temperature at above $500^{\circ}C$. From AFM, it was known that the thin film grown at $400^{\circ}C$ is the densest. Dielectric constant increased with increasing temperature up to $400^{\circ}C$ at 100 kHz and dramatically decreased at the higher temperature. A aspect of dissipation factor was the exact opposite of dielectric constant. BMZN thin films grown at $400^{\circ}C$ exhibited a high dielectric constant of 60.9, a low dissipation factor of 0.007 at 100 kHz.

Thermal Formation of Polycyclic Aromatic Hydrocarbons from Cyclopentadiene (CPD)

  • Kim, Do-Hyong;Kim, Jeong-Kwon;Jang, Seong-Ho;Mulholland, James A.;Ryu, Jae-Yong
    • Environmental Engineering Research
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    • 제12권5호
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    • pp.211-217
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    • 2007
  • Polycyclic aromatic hydrocarbon growth from cyclopentadiene (CPD) pyrolysis was investigated using a laminar flow reactor operating in a temperature range of 600 to $950^{\circ}c$. Major products from CPD pyrolysis are benzene, indene and naphthalene. Formation of observed products from CPD is explained as follows. Addition of the cyclopentadienyl radical to a CPD $\pi$-bond produces a resonance-stabilized radical, which further reacts by one of three unimolecular channels: intramolecular addition, C-H bond $\beta$-scission, or C-C bond $\beta$-scission. The intramolecular addition pathway produces a 7-norbornenyl radical, which then decomposes to indene. Decomposition by C-H bond $\beta$-scission produces a biaryl intermediate, which then undergoes a ring fusion sequence that has been proposed for dihydrofulvalene-to-naphthalene conversion. In this study, we propose C-C bond $\beta$-scission pathway as an alternative reaction channel to naphthalene from CPD. As preliminary computational analysis, Parametric Method 3 (PM3) molecular calculation suggests that intramolecular addition to form indene is favored at low temperatures and C-C bond $\beta$-scission leading to naphthalene is predominant at high temperatures.

Association of wheezing phenotypes with fractional exhaled nitric oxide in children

  • Shim, Jung Yeon
    • Clinical and Experimental Pediatrics
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    • 제57권5호
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    • pp.211-216
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    • 2014
  • Asthma comprises a heterogeneous group of disorders characterized by airway inflammation, airway obstruction, and airway hyperresponsiveness (AHR). Airway inflammation, which induces AHR and recurrence of asthma, is the main pathophysiology of asthma. The fractional exhaled nitric oxide (FeNO) level is a noninvasive, reproducible measurement of eosinophilic airway inflammation that is easy to perform in young children. As airway inflammation precedes asthma attacks and airway obstruction, elevated FeNO levels may be useful as predictive markers for risk of recurrence of asthma. This review discusses FeNO measurements among early-childhood wheezing phenotypes that have been identified in large-scale longitudinal studies. These wheezing phenotypes are classified into three to six categories based on the onset and persistence of wheezing from birth to later childhood. Each phenotype has characteristic findings for atopic sensitization, lung function, AHR, or FeNO. For example, in one birth cohort study, children with asthma and persistent wheezing at 7 years had higher FeNO levels at 4 years compared to children without wheezing, which suggested that FeNO could be a predictive marker for later development of asthma. Preschool-aged children with recurrent wheezing and stringent asthma predictive indices also had higher FeNO levels in the first 4 years of life compared to children with wheezing and loose indices or children with no wheeze, suggesting that FeNO measurements may provide an additional parameter for predicting persistent wheezing in preschool children. Additional large-scale longitudinal studies are required to establish cutoff levels for FeNO as a risk factor for persistent asthma.

A new Korean red algal species, Haraldiophyllum udoensis sp. nov. (Delesseriaceae, Rhodophyta)

  • Kim, Myung-Sook;Kang, Jeong-Chan
    • ALGAE
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    • 제26권3호
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    • pp.211-219
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    • 2011
  • The genus Haraldiophyllum comprises seven species worldwide. Six of these are endemics with limited distributions, whereas the type species H. bonnemaisonii has been reported from the Atlantic Ocean. In Korea, H. bonnemaisonii has been previously recorded from the southern coast. During a red algal collection at Udo, Jeju Island, Korea, we found a potentially undescribed Haraldiophyllum species and analyzed its morphology and rbcL sequences. Herein we describe a new species, H. udoensis sp. nov., and compare our Udo specimen to similar congeners. This new species is characterized by one or several elliptical blades on a short cylindrical stipe with fibrous roots, blades that are monostromatic except at the base and on reproductive structures, a lack of network and microscopic veins, entire margins, lack of proliferations, growth through many marginal initials, and two distinct tetrasporangia layers. A phylogenetic rbcL sequence analysis demonstrated H. udoensis was distinct from the United Kingdom's H. bonnemaisonii, as well as from other species. Morphological and sequence data indicated a previous misidentification of H. udoensis as the type species H. bonnemaisonii. Based on maximum likelihood analysis, Myriogramme formed a sister clade with H. udoensis, with relatively low bootstrap support.

결함 상세를 포함하는 철근콘크리트 전단벽의 수치 모델에 관한 실험적 평가 (Experimental Assessment of Numerical Models for Reinforced Concrete Shear Walls with Deficient Details)

  • 전성하;박지훈
    • 한국지진공학회논문집
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    • 제20권4호
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    • pp.211-222
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    • 2016
  • Reinforced concrete shear walls with deficient reinforcement details are tested under cyclic loading. The deficiency of reinforcement details includes insufficient splice length in U-stirrups at the ends of horizontal reinforcement and boundary column dowel bars found in existing low- to mid-rise Korean buildings designed non-seismically. Three test specimens have rectangular, babel and flanged sections, respectively. Flexure- and shear-controlled models for reinforced concrete shear walls specified in ASCE/SEI 41-13 are compared with the flexural and shear components of force-displacement relation extracted separately from the top displacement of the specimen based on the displacement data measured at diverse locations. Modification of the shear wall models in ASCE/SEI 41-13 is proposed in order to account for the effect of bar slip, cracking loads in flexure and shear. The proposed modification shows better approximation of the test results compared to the original models.

Development and Stability Evaluation of Enteric Coated Diclofenac Sodium Tablets Using AquaPolish E.

  • Zaid, A.N.;Fadda, A.M.;Nator, S.;Qaddumi, A.
    • Journal of Pharmaceutical Investigation
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    • 제41권4호
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    • pp.211-215
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    • 2011
  • The aim of this study was to develop a stable enteric coated diclofenac sodium (DFS) tablets using Aqua-Polish E without using a subcoat. DFS uncoated tablets were manufactured through the non direct compression process. AquaPolish E white aqueous coating dispersion was used as enteric coating material. This film forming polymer is a mixture of selected polymethacrylic/ethylacrylate copolymers. The stability of the obtained enteric coated tablets was evaluated according to ICH guidelines. No signs of disintegration or cracking was observed when they placed in 0.1N HCl solution (pH1.2), but they were completely disintegrated within 10 minutes when they placed in buffered solution at pH6.8. Dissolution test was also conducted by placing tablets in 0.1 N HCl for 2 hours and then 1 hour in phosphate buffer at pH 6.8. Less than 0.9 % of drug was released in the acidic phase and up to 97% in the basic medium. These findings suggest that aqueous enteric coating with AquaPolish E system is an easy and economical approach for preparing stable DFS enteric coat without the use of a subcoating layer.

단일주파수분석을 이용한 심폐소생술 흉부압박깊이 추정 (Estimation of Chest Compression Depth during Cardiopulmonary Resuscitation by using Single Frequency Analysis)

  • 유원상;강성민;최성욱
    • 대한의용생체공학회:의공학회지
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    • 제38권4호
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    • pp.211-217
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    • 2017
  • During the emergency situation such as cardiac arrest, cardiopulmonary resuscitation(CPR) is the most important treatment to maintain patient's blood circulation. Since the quality of CPR can not be easily measured or evaluated by the eye, an assistive device with an accelerometer can help to assess the pressure depth of CPR. In this study, we propose a single frequency analysis method to reduce the error of the accelerometer by extracting only one frequency component from the Fourier transform process. To verify the effectiveness of the single frequency analysis, acceleration data at CPR conditions were measured at a sampling rate of 50 / sec using a wristband equipped with an acceleration sensor. Then, We compared the existing distance estimation method and the single frequency analysis method using the measured data. The amplitude value proportional to the compression depth was obtained by applying the single frequency analysis method.

스퍼터링 공정 압력이 InZnO 박막트랜지스터의 광학 및 전기적 특성에 미치는 영향 (Effect of Sputtering Working Pressure on the Optical and Electrical Properties of InZnO Thin-Film Transistors)

  • 박지민;김형도;장성철;김현석
    • 한국재료학회지
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    • 제30권4호
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    • pp.211-216
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    • 2020
  • Amorphous In-Ga-Zn-O (a-IGZO) thin film transistors, because of their relatively low mobility, have limits in attempts to fulfill high-end specifications for display backplanes. In-Zn-O (IZO) is a promising semiconductor material for high mobility device applications with excellent transparency to visible light region and low temperature process capability. In this paper, the effects of working pressure on the physical and electrical properties of IZO films and thin film transistors are investigated. The working pressure is modulated from 2 mTorr to 5 mTorr, whereas the other process conditions are fixed. As the working pressure increases, the extracted optical band gap of IZO films gradually decreases. Absorption coefficient spectra indicate that subgap states increase at high working pressure. Furthermore, IZO film fabricated at low working pressure shows smoother surface morphology. As a result, IZO thin film transistors with optimum conditions exhibit excellent switching characteristics with high mobility (≥ 30㎠/Vs) and large on/off ratio.