• Title/Summary/Keyword: bi-jeung

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Preparation of $Bi_2Te_3$ Thermoelectric Materials by Co-precipitation Method (공침법을 이용한 $Bi_2Te_3$ 열전재료의 제조)

  • Kim, Dong-Hwan;Im, Hee-Joong;Je, Koo-Chul;Kang, Young-Jin;Ahn, Jeung-Sun;Tadaoki Mitani;Nam, Tae-Hyun;Shim, Young-Jae
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.167-167
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    • 2003
  • 현대 산업이 발전함에 따라 전자부품의 초소형화, 고성능화가 요구되어지고 있으며, 이러한 점에 부응하기 위하여 Pottier 효과를 이용하여 국부냉각이 가능한 열전재료에 대한 많은 연구가 이루어지고 있다. 열전재료에는 사용온도 영역에 따라 여러 종류가 있지만, Bi-Te계 열전재료는 상온영역에서 가장 성능지수(Z=$\alpha$$^2$$\sigma$/$textsc{k}$, $\alpha$는 Seebeck 계수, $\sigma$는 전기전도도, $textsc{k}$는 열전도도)가 높아 각종 냉각소자로서 사용되어 지고 있다. 하지만, 초소형 전자부품의 국부냉각을 위해서는 성능지수의 향상, 특히, 저온 영역에서의 성능지수의 향상이 요구되고 있다. 본 연구에서는 Bi-Te계 열전재료의 성능지수를 향상시키기 위하여, 열전도도의 저하에 의한 성능지수의 향상을 연구목적으로 하였다 열전도도는 전자에 의한 열전도도(K$_{e}$)와 phonon에 의한 열전도도(K$_{p}$)로 이루어지며, 전기전도도에 큰 영향을 미치지 않는 결정립 사이즈영역에서 결정립의 크기를 미세화 하면, 결정입계에서의 phonon의 산란이 증가하여 phonon에 의한 열전도도를 저하시킴으로서 성능지수의 향상이 기대된다. 따라서 본 연구에서는 나노사이즈 분말의 제조에 많이 이용되며 입자크기의 조절이 용이한 공침법을 이용하여 Bi-Te계 열전재료 분말을 제조하고 열전재료에의 적용가능성을 검토하였다.

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A Case Report of Central Post-Stroke Pain Patient Treated by Moxibustion Therapy (뇌졸중 후 중추성 통증으로 인한 좌반신비증 치험 1례)

  • Lee, Mirim;Lee, Yuri;Minl, Kyungdong;Cho, Ki-ho;Mun, Sang-Kwan;Jung, Woo-sang
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.16 no.1
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    • pp.35-40
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    • 2015
  • ■ Objectives The purpose of this clinical study is to evaluate the effect of moxibustion on a patient with left side paresthesia induced by central post-stroke pain. ■ Methods A patient with left side paresthesia diagnosed with central post-stroke pain was treated with moxibustion, herbal medication, acupuncture, electro-acupuncture(EA). Then we evaluated the improvement by Mcgill pain score and Questionnaire of BiJeung. ■ Results Decrease of Mcgill pain score, Questionnaire of BiJeung were observed after the moxibustion treatment. ■ Conclusion This study proved the effect of moxibustion treatment on left side paresthesia due to central post-stroke pain.

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Shubnikov-de Haas Oscillations in an Individual Single-Crystalline Semimetal Bismuth Nanowire (단결정 반금속 비스무스 단일 나노선의 Shubnikov-de Haas 진동)

  • Kim, Jeong-Min;Ham, Jin-Hee;Shim, Woo-Young;Lee, Kyoung-Il;Jeon, Kye-Jin;Jeung, Won-Young;Lee, Woo Young
    • Korean Journal of Materials Research
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    • v.18 no.2
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    • pp.103-106
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    • 2008
  • The magneto-transport properties of an individual single crystalline Bi nanowire grown by a spontaneous growth method are reported. A four-terminal device based on an individual 400-nm-diameter nanowire was successfully fabricated using a plasma etching technique that removed an oxide layer that had formed on the surface of the nanowire. Large transverse ordinary magnetoresistance (1401%) and negative longitudinal ordinary magnetoresistance (-38%) were measured at 2 K. It was observed that the period of Shubnikov-de Haas oscillations in transverse geometry was $0.074^{T-1}$, $0.16^{T-1}$ and $0.77^{T-1}$, which is in good agreement with those of bulk Bi. However, it was found that the period of SdH oscillation in longitudinal geometry is $0.24^{T-1}$, which is larger than the value of $0.16^{T-1}$ reported for bulk Bi. The deviation is attributable to the spatial confinement arising from scattering at the nanowire surface boundary.

Electronic Structures of Graphene Intercalated by Oxygen on Ru(0001): Scanning Tunneling Spectroscopy Study

  • Jang, Won-Jun;Jeon, Jeung-Hum;Yoon, Jong-Keon;Kahng, Se-Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.114-114
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    • 2011
  • Graphene is the hottest topic in condensed-matter physics due to its unusual electronic structures such as Dirac cones and massless linear dispersions. Graphene can be epitaxially grown on various metal surfaces with chemical vapor deposition (CVD) processes. Such epitaxial graphene shows modified electronic structures caused by substrates. In the method for removal of the effect of substrate, there are bi, tri-layer graphene, gold intercalation, and oxygen intercalation. Here, We will present the changes of geometric and electronic structure of graphene grown on Ru(0001) by oxygen intercalation between graphene and Ru(0001). Using Scanning tunneling microscopy (STM) and spectroscopy (STS), we observed the aspect that the band gap features near the fermi level of graphene on Ru(0001) system is shifted and narrow. Based on the observed results, two effects by intercalated oxygen were considered.

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Clinical Study of Oriental-Western collaborative medical treatment on 1 case of patient with Suppurative Arthritis (Suppurative arthritis 환자(患者) 1례(例)의 한(韓)·양방(洋方) 겸치를(兼治)를 통(通)한 임상적(臨床的) 고찰(考察))

  • Ha, Chi-Hong;Cho, Myung-Rae
    • Journal of Acupuncture Research
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    • v.17 no.3
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    • pp.277-285
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    • 2000
  • By process of treatment for a case which diagnosed as suppurative arthritis and admitted from the 5th, October, 1999 to the 15th, November, 1999, the results are as follows. Method & Results : In the earlier days of admission, this patient was diagnosed as damp-heat(濕熱) and medicated Cheongyeolsaseup-tang(qingrexieshi-tang). As the result, heating, pain in both knees and heating in both lmees are improved. In the later days of admission, this patient was diagnosed as impairment of the liver and kidney(肝腎虛損) and medicated Samgi-eum(sanqi-yin). As the reslut, weakness in lower limbs is improved. Conclusion : I consider that the rate of recovery for other infectious diseases including suppurative arthritis can be maximized by accumulation of clinical experiences and continuous research through both western medical treatment and oriental medical treatment.

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Design and Implementation of a Slot Antenna with Bazooka Balun for PCS Repeater (Bazooka balun을 이용한 PCS 중계기용 슬롯 안테나의 설계 및 구현)

  • Choi, Won-Jun;Kim, Che-Young;Jang, Byung-Chan;Park, Jeung-Keun
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.105-106
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    • 2007
  • A slot antenna with bazooka balun is designed and implemented for PCS repeater. The proposed antenna improved the return loss and radiation pattern of the slot antenna as combining with the bazooka balun. The antenna was designed by using 3D simulations program, MWS (Microwave Studio). The test result of the slot antenna shows that the return loss is under -10 [dB] for all frequency bands of interests in PCS and maximum gain is about 5.59 [dBi]. And the antenna also shows omni-directional radiation pattern.

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A Study on the quality of Life by jansang(臟象)'s relational analysis and Byunjeung(辨證)'s type according to Tinnitus's aspect (이명(耳鳴)의 양상에 따른 장상적(臟象的) 상관(相關) 분석 및 변증(辨證) 형태별 삶의 질에 관한 연구)

  • Kim, Gyung-Jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.3
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    • pp.20-30
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    • 2017
  • Background : Tinnitus is common disorder with many possible causes and a symptom of many different diseases but has no effective treatment. Approximately 20% of tinnitus patients experience the disorder to a degree that their quality of life and productivity are impaired. Objectives : 1. Through symptoms of tinnitus, we tried to find out the relationship of Heo-sil(虛實) and Jang bu byun jeung(臟腑辨證). 2. By testing THI, we tried to evaluate the quality of life between high-grade tiny noise and low-grade roar tinnitus patients group. Methods : 34 patients were recruited in this study who was ill with tinnitus. They wrote out the questionnaire about tinnitus and the tinnitus Handicap Inventory(THI). Results : 1. The vast majority of high-grade tiny noise patients are Heojeung(虛症). 2. The vast majority of low-grade roar patients are Siljeung(實症). 3. The number of patients with intermittent and persistent tinnitus is similar. 4. In high-grade tiny noise, Sin jung hyu son type(腎精虧損型) patients are less comfortable with quality of life than Bi wi heo yak type(脾胃虛弱型) patients. 5. Low-grade roar patients are less comfortable with quality of life than high-grade tiny noise atients Conclusions : Jang bu byun jeung(臟腑辨證) and Distinguishing between Heo(虛) and Sil(實) is expected to have positive effects on tinnitus treatment.

Decontamination of Interior of Field Tent Employed Geobacillus stearothermophilus Spores using a Hydrogen Peroxide Vapor System (과산화수소증기 시스템을 이용한 야전용 천막 내 Geobacillus stearothermophilus 아포 제독)

  • Yoon, Sung Nyo;Kim, Yun Ki;Jeung, Jeung Hoon;Yoo, Hyun Sang;Min, Kyung Yool;Kim, Min Cheol;Kim, Se Kye;Ryu, Sam Gon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.5
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    • pp.669-674
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    • 2016
  • The purpose of this study is to demonstrate the suitability of hydrogen peroxide($H_2O_2$) vapor system for platform interior decontamination. Geobacillus stearothermophilus biological indicator(BI) strips and a field tent were used as a biological simulant and as a simulated platform, respectively. Decontamination was performed based on injection rates and tent sizes with exposure time 60 minutes. We standardized the conditions for the field tent decontamination : 8.0 g/min for $30m^3$($H_2O_2$ vapor concentration of 150~500 ppm, relative humidity of 50 %) and 12.0 g/min for $60m^3$($H_2O_2$ vapor concentration of 250~400 ppm, relative humidity of 55 %). Thus we suggest the system is one of the possible candidates for decontamination of platform interiors.

Antenna-Diplexer Module for Cellular/SDMB Band Using LTCC Technology (LTCC 공법을 사용한 Cellular/SDMB 안테나-다이플렉서 모듈)

  • Ha, Jeung-Uk;Chang, Ki-Hun;Yoon, Young-Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.7
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    • pp.774-783
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    • 2007
  • This paper presents an integrated packaging antenna-diplexer module for wireless communication systems in the Cellular and SDMB band. The design and the realization of the proposed one are experimentally analyzed and discussed. It consists of a dual-resonance antenna and a diplexer with a multi-layer LTCC(${\varepsilon}_r=7.8,\;tan\;{\delta}=0.0043$) technology with integration capability and low loss. The dual-resonance antenna of the proposed module has the meander line structure for size reduction and has the shorting structure of an inverted F antenna to achieve good impedance matching. The diplexer of the proposed module was designed with the combination of low pass filter(LPF) and high pass filter(HPF). Decreasing the mutual interference between them provides a high isolation characteristic. The proposed antenna-diplexer module with dimensions of $27.5{\times}12.0{\times}2.2mm$ operates within a range from 813 MHz to 902 MHz for the cellular band and from 2,586 MHz to 2,655 MHz for the SDMB band. And the measured gain of the fabricated module is -1.96 dBi for Cellular band and -5.43 dBi for SDMB band. The parameters for the antenna-diplexer module are investigated and the several performances are discussed.

A study on the design of an Dual Inverted-F Internal Antenna for the WLAN`s Band (WLAN대역의 듀얼 역-F형 내부 안테나 설계에 관한 연구)

  • Kang, Jeong-Jin;Kang, Seo;Jeung, Seung-Il;Kim, Wan-Sik;Lee, Jong-Arc
    • Journal of IKEEE
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    • v.7 no.2 s.13
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    • pp.223-229
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    • 2003
  • In this thesis, the characteristics of an inverted-F antenna for the 2.4GHz and 5.8GHz zwirless local area network(WLAN) have been analysed in terms of the variation of design parameters. The antenna can be integrated on WLAN for notebook printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed. By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 170MHz, 500MHz frequency bandwidth ,VSWR is 1.6, 1.14 and 3.5dBi gain.

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