• 제목/요약/키워드: Chang Hyun-kwang

검색결과 964건 처리시간 0.037초

검은비늘버섯 품종 '진황'의 특성 및 재배법 (Cultivation method and characterization of commercial strain 'Jinhwang' in Pholiota adiposa)

  • 공원식;유영복;전창성;유창현;조용현;장후봉;김광호
    • 한국버섯학회지
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    • 제4권3호
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    • pp.106-110
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    • 2006
  • 우수한 약리기능성을 보이는 검은비늘버섯의 병재배에 적합한 새로운 품종 진황을 교잡육종법으로 육성하였다. 진황은 포플라톱밥을 이용한 병제배와 폐면을 이용한 상자재배가 모두 가능하여 재배농가에서 생산이 용이하나, 약용 또는 기능성버섯으로서의 인지도가 낮으므로 소비 확대를 위한 약리효과의 홍보가 필요하다. 진황 검은비늘버섯의 주요특성은 다음과 같다. 가. 균사배양 최적용도는 $25^{\circ}C$ 자실체발생 및 생육온도는 $15 {\sim}18^{\circ}C$이다. 나. 자실체의 색깔은 황갈색이며 갓표면에 흰색~갈색의 인피가 덮혀 있으며 점성이 있다. 다. 병당 유효개채수가 평균 26개로 많고 대도 굵어 품질이 양호하다.

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CaCO3 첨가에 따른 저온소결 PNW-PMN-PZT 세라믹스의 압전 및 유전특성 (Piezoelectric and Dielectric Characteristics of Low Temperature Sintering PNW-PMN-PZT Ceramics according to CaCO3Addition)

  • 류주현;이상호;이창배;송현선;정광현;정영호;박덕원
    • 한국전기전자재료학회논문지
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    • 제18권3호
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    • pp.243-247
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    • 2005
  • In this study, in order to develop low temperature sintering ceramics for ultrasonic vibrator application, PNW-PMN-PZT system ceramics were manufactured according to the amount of CaCO$_3$ addition, and their piezoelectric, dielectric and microstructural characteristics were investigated. The ceramic specimens could be sintered at sintering temperature below 1000 $^{\circ}C$ due to the effect of Li$_2$CO$_3$-CaCO$_3$ liquid phase produced by the reaction of Li$_2$CO$_3$ and CaCO$_3$. At 0.2 wt% Li$_2$CO$_3$ and 0.25 wt% CaCO$_3$ added specimen sintered at 920 $^{\circ}C$, the density, electromechanical coupling factor(k$_{p}$), mechanical quality factor(Q$_{m}$) and dielectric constant showed the optimal value of 7.78 g/㎤, 0.49, 1396, and 1300, respectively, for ultrasonic vibrator application.ion.

$La_2O_3$ 첨가에 따른 무연 BNKT세라믹의 압전 특성 (Piezoelectric properties of Pb-free BNKT ceramics with the amount of $La_2O_3$ addition)

  • 이현석;이창배;류주현;정영호;홍재일;정광현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.145-149
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    • 2004
  • In this study, leed-free piezoelectric ceramics were investigated for pressure sensor applications as a function of the amount of $La_2O_3$ addition at BNKT system. With increasing amount of $La_2O_3$ addition, density and dielectric constant were increased up to 0.9wt% addition and decreased after 0.9wt% addition, electromechanical coupling factor$(k_p)$ and mechanical quality factor$(Q_m)$ showed the maximum values at 0.2wt% addition and decreased after 0.2wt% addition. The $k_p$, density, dielectric constant and $Q_m$ were showed the optimum values of 0.40, $5.71g/cm^3$, 768 and 118 at $La_2O_3$ 0.2wt% addition, respectively.

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저온소결 압전변압기용 PMW-PMN-PZT 의 압전특성 (Piezoelectric Characteristics of Low temperature sintering PMW-PMN-PZT Ceramics for Piezoelecric Transformer)

  • 이현석;정광현;류주현;박창엽;류성림;정영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.214-215
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    • 2005
  • In this paper, in order to develop low temperature sintering piezoelectric ceramics for piezoelectric transformer, PMW-PMN-PZT ceramics using 0.25wt%$CaCO_3$ and 0.2wt%$Li_2CO_3$ as sintering aids were fabricated according to the variation of amount of PMW and Zr/Ti ratio. Specimens could be sintered at 900$^{\circ}C$ by adding sintering aids. As Zr/Ti ratio was increased, kp was increased and Qm was decreased by approaching MPB region, and kp showed the largest value of 0.58 at Zr/Ti:50/50. The variation of amount of PMN substitution affected the liquid phase sintering of the ceramics using sintering aids, and decreased piezoelectric properties.

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$CeO_2$첨가에 따른 저온소결 PSN-PZT세라믹스의 유전 및 압전 특성 (Dielectric and Piezoelectric Properties of Low temperature sintering PSN-PZT ceramics with $CeO_2$ addition)

  • 정광현;류주현;오동언;송현선;정회승;박창엽;이덕출
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.300-303
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    • 2003
  • [ $0.91(PSN-PZT)-0.05BF-0.04PNW+0.3wt%MnO_2+0.6wt%CuO+xwt%CeO_2$ ] ceramics were fabricated with the variations of $CeO_2$ addition at the sintering temperature of $950^{\circ}C$ and their microstructure and dielectric and piezoelectric characteristics were investigated. As the amount of $CeO_2$ addition increased, the grain size, density and electromechanical coupling factor(kp) were increased and the mechanical quality factor(Qm) was decreased. At the $0.3wt%CeO_2$, density, grain size and electromechanical factor(kp) showed the maximum value of $7.87g/cm^3$, $3.22{\mu}m$ and 0.5, respectively. However, mechanical quality factor(Qm) showed the minimum value of 807 at the $0.5wt%CeO_2$.

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$Al_2O_3$ 세라믹 유전체 오존발생기의 방전면적 특성 (Discharge Area Characteristics of Ozonizer with $Al_2O_3$ Dielectric)

  • 박현미;송현직;이상근;임창호;윤병한;김종현;이광식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.2214-2216
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    • 2005
  • This paper is researched discharge and ozone generation characteristics of ozonizer using $Al_2O_3$ Ceramic dielectric. The discharge characteristics with variation of the discharge electrode area is studied. The characteristics of ozone concentration. ozone generation and ozone yield were measured to discharge power, discharge electrode area and supplied gas flux for oxygen and air. The solubility of ozone for water concentrations and ozone generations proportional to discharge power and discharge electrode area. Ozone yield has slowly increase with Increasing discharge power at high flow-rate. As the result, the maximum values of ozone characteristics ozone generation and ozone yield, can be obtained 5817[ppm] and 36[g/kWh]. We make enough the ozone concentration as the air in the home. An electric discharge electrode area is apt to shrink gradually into a miniaturization trend of the ozonizer but the enlargement of the occurrence flight of the electric discharge area gives the characteristic enhance the aid in the identity condition through the structure improvement.

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신남산 유도체 I, Cinnamanilide 유도체의 가수분해 메카니즘과 반응속도론적 연구 (Cinnamic Acid Derivatives I, The Kinetics and Mechanism of the Hydrolysis and Synthesis of Cinnamanilide Derivatives)

  • 이기창;황용현;이광일;정택서;박광하
    • 한국응용과학기술학회지
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    • 제6권2호
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    • pp.59-65
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    • 1989
  • The rate constants of the hydrolysis of cinnamanilide derivatives were determined UV spectrometry in $H_2SO_4\;(5{\sim}20N)$, NaOH($5{\sim}11N)\;at\;50{\sim}110^{\circ}C$ and rate equation could be applied over a strong acid and strong base were obtained. Final product of the hydrolysis was a cinnamic acid. The ${\rho}$ values obtained from the slope of linear plots of log $k_{abs}$ vs. Hammet $t{\sigma}$ constants were slightly negatives, Substituents on cinnamanilide showed a relatively small effect, with hydrolysis facilitated be electron donating group. Activation energy(Ea)was also calculated for the hydrolysis of the cinnamanilide. From this reaction rate equation, substituent effect and experimental of rate constants, that the hydrolysis of cinnamanillde was Initiated by the netural molecule of $H_2O$ which do not dissociate at strong acid, and proceeded by hydroxide ion at strong base.

두경부 악성종양에서 경부임파절전이에 대한 CT Scan의 진단적 의의 (The Correlation between CT Images and Pathological Findings in Metastatic Cervical Lymph Nodes)

  • 이원상;김광문;정광현;장훈상;김지우;김동익
    • 대한두경부종양학회지
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    • 제4권1호
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    • pp.5-11
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    • 1988
  • CT examination has been used in the preoperative examination of patients with head and neck cancer. The accuracy of CT in detecting nodal metastases has not been well established. We studied 35 patients (41 neck specimens) with head and neck cancer who underwent neck dissection. Surgical pathologic findings were compared with preoperative CT scan to establish the diagnostic accuracy for cervical lymph node metastases. The results of physical examination, CT scans of neck and histologic examinations were compared each other. The overall diagnostic accuracy of CT was 83.3%. Comparison with clinical accuracy shows the CT scan to be superior to the clinical examination in spite of careful physical examination, particularly in detecting occult metastases.

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Effect of Graphene on Growth of Neuroblastoma Cells

  • Park, Hye-Bin;Nam, Hyo-Geun;Oh, Hong-Gi;Kim, Jung-Hyun;Kim, Chang-Man;Song, Kwang-Soup;Jhee, Kwang-Hwan
    • Journal of Microbiology and Biotechnology
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    • 제23권2호
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    • pp.274-277
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    • 2013
  • The unique properties of graphene have earned much interest in the fields of materials science and condensedmatter physics in recent years. However, the biological applications of graphene remain largely unexplored. In this study, we investigate the cell culture conditions, which are exposed to graphene onto glass and $SiO_2$/Si using human nerve cell line, SH-SY5Y. Cell viability was 84% when cultured on glass and $SiO_2$/Si coated with graphene as compared to culturing on polystyrene surface. Fluorescence data showed that the presence of graphene did not influence cell morphology. These findings suggest that graphene may be used for biological applications.

Enflurane으로 인하여 발생한 마취 중 급성과민증 (Intraoperative Anaphylatic Reaction to Enflurane -A Case Report -)

  • 박창주;서광석;김현정;최진영;염광원
    • 대한치과마취과학회지
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    • 제4권1호
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    • pp.25-29
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    • 2004
  • Anaphylactic reactions to anesthetic drugs could potentially produce life-threatening immune-mediated crisis. Most published reports are associated with neuromuscular blockers and anaphylactic reactions to inhalation anesthetics are rare. A 25-year-old male patient with no significant medical history and no previous abnormal drug reaction was scheduled for orthognathic surgery under general anesthesia. After uneventful anesthetic induction and nasotracheal intubation, generalized urticaria and erythema were detected during the maintenance period with $O_2-N_2O$-enflurane. No severe changes of vital signs and no ventilation problem were accompanied. The operation was cancelled and the cutaneous lesions were faded away during the recovery with 100% $O_2$. The skin-prick and intradermal tests showed that he was hypersensitive to all halogenated inhalation anesthetics including enflurane and not to intravenous anesthetics and neuromuscular blockers. The re-operation was safely carried out under intravenous anesthesia with propofol-fentanyl-vecuronium. We report this case of intraoperative anaphylactic reaction to enflurane with literature review.

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