• Title/Summary/Keyword: PNP

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Removal of heavy metal and Hydrogen sulfide/Nitrophenol using Mackban-stone (맥반석을 이용한 중금속과 악취물질/nitrophenol의 제거)

  • Quen, Zhe-Xue;Yin, Cheng-Ri;Jin, Yin-Shu;Seok, Mi-Soo;Lee, Sung-Taik
    • Journal of the Korea Organic Resources Recycling Association
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    • v.9 no.2
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    • pp.45-51
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    • 2001
  • Mackban-stone effectively removed heavy metals, such as Fe, Cu, Cd, and Zn, with best removal of Fe and Cu. And the removal of heavy merals related with ion exchange of Ca. Mackban-stone is also an efficient deodorant of hydrogen sulfide and ammonia and inhibited the growth of E coli. The degradation rare of 4-nitropheno1 by Nocardioides sp. PNP101 and 2,4-dinitrophenol by Strain CJ1 and Rhodococcus sp. DNP 505 are increased by Mackbane-srone.

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Comparative Evaluation of Physicochemical Properties of Pine Needle Powders Prepared by Different Drying Methods

  • Chung, Ha-Sook;Lee, Jun Ho
    • Preventive Nutrition and Food Science
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    • v.20 no.2
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    • pp.143-147
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    • 2015
  • Systematic study of how different drying methods, namely hot-air drying, vacuum-drying, and freeze-drying, affect color, browning index, degree of rehydration, water solubility, and vitamin C content is critical for utilizing pine needle powders (PNP) as a novel ingredient in functional foods. Samples prepared by vacuum-drying showed a significantly higher $L^*$-value, whereas higher $a^*$- and $b^*$-values were detected in the hot-air dried samples (P<0.05). The browning index was significantly higher in samples prepared by vacuum-drying compared to samples prepared by freeze-drying (P<0.05). Freeze-dried PNP exhibited a significantly higher degree of rehydration than hot-air dried samples (P<0.05). Water solubilities of freeze-dried and hot-air dried samples were significantly higher than that of vacuum-dried sample (P<0.05). Vitamin C was less destroyed during freeze-drying compared to hot-air or vacuum-drying (P<0.05). Freeze-dried samples displayed a clear porous structure and appeared to have a bigger space, whereas hot-air dried samples showed lower porosity than vacuum and freeze-dried samples.

A Study on composition of current stable negative resistance circuits. (전류안정부저항회로의 구성에 관한 연구)

  • 박의열
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.10 no.1
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    • pp.9-17
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    • 1973
  • This paper dealt with composition of current stable negatil'e resistance circuit based on Beam resistance of the tube SAMUEL SEBLY suggested. Beam resistance which is decreased by input current increment on definite region of current, accompanied generation of equivalent e. m. f on model circuit. With equivalent e. m. f there appeared increased current on circuit but decrease of terminal voltage. Bloc constructed by above concept induced transistorized circuit which have NPN and a PNP Transistor. Circuit operation predicted and calculated values of negative resistance are coincident with experimental results. A Circuit proposed on this paper sllowed good linearity on Ve-Ji characteristics.

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Purification and Partial Characterization of Thermostable Carboxyl Esterase from Bacillus stearothermophilus L1

  • Kim, Hyung-Kwoun;Park, Sun-Yang;Oh, Tae-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.7 no.1
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    • pp.37-42
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    • 1997
  • A bacterial strain L1 producing a thermostable esterase was isolated from soil taken near a hot spring and identified as Bacillus stearothermophilus by its microbiological properties. The isolated thermostable esterase was purified by ammonium sulfate fractionation, ion .exchange and hydrophobic interaction chromatographies. The molecular weight of the purified enzyme was estimated to be 50,000 by SDS-PAGE. Its optimum temperature and pH for hydrolytic activity against PNP caprylate were $85^{\circ}C$ and 9.0, respectively. The purified enzyme was stable up to $70^{\circ}C$ and at a broad pH range of 4.0-11.5 in the presence of bovine serum albumin. The enzyme was inhibited by phenylmethylsulfonyl fluoride and diethyl p-nitrophenyl phosphate, indicating the enzyme is a serine esterase. The enzyme obeyed Michaelis-Menten kinetics in the hydrolysis of PNPEs and had maximum activity for PNP caproate ($C_6$) among PNPEs ($C_2-C_12$) tested.

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Significant Proteinuria Caused by Posterior Nutcracker Phenomenon (호두까기 증후군으로 인해 발생한 다량의 단백뇨)

  • Lee, Jun-Ho;Kim, Geun-Jung
    • Childhood Kidney Diseases
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    • v.14 no.1
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    • pp.84-88
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    • 2010
  • Posterior nutcracker phenomenon (PNP) was found to be the cause of significant proteinuria in a 10-year-old female. PNP was documented by Doppler ultrasonography and abdominal 3D CT as a cause of her proteinuria. Despite treatment with ACE inhibitor for several months, her persistent and progressive proteinuria lead us to perform a left renal biopsy, which revealed no significant finding except for focal effacement of foot processes. We speculate that nutcracker phenomenon can induce not only orthostatic proteinuria but also significant proteinuria by focal effacement of foot processes.

Effects of Fast Neutron Irradiation on Switching of Silicon Bipolar Junction Transistor

  • Sung Ho Ahn;Gwang Min Sun
    • Journal of Radiation Protection and Research
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    • v.48 no.3
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    • pp.124-130
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    • 2023
  • Background: When bipolar junction transistors (BJTs) are used as switches, their switching characteristics can be deteriorated because the recombination time of the minority carriers is long during turn-off transient. When BJTs operate as low frequency switches, the power dissipation in the on-state is large. However, when BJTs operate as high frequency switches, the power dissipation during switching transients increases rapidly. Materials and Methods: When silicon (Si) BJTs are irradiated by fast neutrons, defects occur in the Si bulk, shortening the lifetime of the minority carriers. Fast neutron irradiation mainly creates displacement damage in the Si bulk rather than a total ionization dose effect. Defects caused by fast neutron irradiation shorten the lifetime of minority carriers of BJTs. Furthermore, these defects change the switching characteristics of BJTs. Results and Discussion: In this study, experimental results on the switching characteristics of a pnp Si BJT before and after fast neutron irradiation are presented. The results show that the switching characteristics are improved by fast neutron irradiation, but power dissipation in the on-state is large when the fast neutrons are irradiated excessively. Conclusion: The switching characteristics of a pnp Si BJT were improved by fast neutron irradiation.

Preparation and Characterization of Chitosan-coated PLGA Nanoparticle (키토산이 코팅된 PLGA 나노입자의 제조 및 특성)

  • Yu, Su-Gyeong;Nah, Jae-Woon;Jeong, Gyeong-Won
    • Applied Chemistry for Engineering
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    • v.32 no.5
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    • pp.509-515
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    • 2021
  • In this study, poly lactic-co-glycolic acid (PLGA) nanoparticles (PNP) were prepared through double (w/o/w) emlusion and emulsifying solvent-evaporation technique using PLGA, which has biocompatibility and biodegradability. To maximize stability and bioavailability of the particles, chitosan-coated PLGA nanoparticles (CPNP) were prepared by charge interaction between PNP and chitosan. We demonstrated that CPNP can be utilized as a drug carrier of oral administration. The chemical structure of CPNP was analyzed by 1H-NMR and FT-IR, and all characteristic peaks appeared, confirming that it was successfully prepared. In addition, particle size and zeta potential of CPNP were analyzed using dynamic light scattering (DLS) while morphological images were obtained using transmission electron microscope (TEM). Thermal decomposition behavior of CPNP was observed through thermogravimetric analysis (TGA). In addition, the cytotoxicity of CPNP was confirmed by MTT assay at HEK293 and L929 cell lines, and it was proved that there is no toxicity confirmed by the cell viability of above 70% at all concentrations. These results suggest that the CPNP developed in this study may be used as an oral drug delivery carrier.

A Study of Low-Voltage Low-Power Linear Transconductor (저전압 저전력 선형 트랜스컨덕터에 관한 연구)

  • 김동용;신희종;차형우;정원섭
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.967-970
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    • 1999
  • A novel linear transconductor for low-voltage low-power signal processing is proposed. The transconductor consists of a pnp differential-pair and a npn differential-pair which are biased by local negative feedback. The simulation results show that the transcondcutor with transconductance of 50 $mutextrm{s}$ has a linearity error of 0.05% and the power dissipation is 2.44 ㎽ over an input linear range from -2V to +2V at supply voltage $\pm$3V.

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A Study on the SPICE Model Parameter Extraction Method for the BJT DC Model (BJT의 DC 해석 용 SPICE 모델 파라미터 추출 방법에 관한 연구)

  • Lee, Un-Gu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.9
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    • pp.1769-1774
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    • 2009
  • An algorithm for extracting the BJT DC model parameter values for SPICE model is proposed. The nonlinear optimization method for analyzing the device I-V data using the Levenberg-Marquardt algorithm is proposed and the method for calculating initial conditions of model parameters to improve the convergence characteristics is proposed. The base current and collector current obtained from the proposed method shows the root mean square error of 6.04% compared with the measured data of the PNP BJT named 2SA1980.

A study on the experimental fabrication and analysis of power IGBT (Power IGBT의 개발에 관한 연구)

  • 성만영;김영식;박정훈;박성희
    • Electrical & Electronic Materials
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    • v.6 no.3
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    • pp.261-268
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    • 1993
  • LIGBT의 전압-전류 특성을 디자인 파라미터와 공정 파라미터를 포함한 SPICE Simulation으로 확인하였다. 중요한 파라미터는 p-body와 n$^{-}$층 그리고 p$^{+}$ 애노드로 구성된 pnp bipolar transistor의 수평전류이득이었다. 이 전류 이득은 Ebers-Moll등식으로 얻었다. LIGBT의 On 저항은 채절 저항(R$_{E}$ )과 인가된 게이트 전압에 종속되는 유효 벌크 저항(R2)으로 구성되며 On 저항의 해석과 모델링은 디바이스의 디자인 조건을 최적화하기 위해서 기하학적 구조와 도핑 프로파일에 따른 물리적 특성으로부터 전개하여 특성해석을 위한 모델링을 실시하여 제시하였다.

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