• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.2
• /
• pp.279-285
• /
• 1993

It is important to understand the interrelationship between adsorption, equilibrium and mass transport in efficient design and operation of the granular activated carbon(GAC) adsorption systems. In this study, the micro-diameter-depth adsorption system(MIDDAS) technique was developed to estimate equilibrium and mass transport parameters, which were utilized to simulate adsorption and mass transport phenomena dynamically and mathematically. The homogeneous surface diffusion model(HSDM) utilizing the estimated equilibrium and mass transport parameters including the film transfer coefficients and surface diffusivities from the MIDDAS technique, successfully predicted competitive adsorption, desorption and chromatographic displacement effects. In the binary solute system of p-chlorophenol(PCP) and p-nitrophenol(PNP), PCP was displaced by PNP and the HSDM could predict successfully. While the HSDM described the desorption breakthrough curves for PCP, PNP and PTS well when complete reversible adsorption was assumed, the desorption breakthrough curves for DBS could be predicted after subsequent incorporation of the degree of irreversibility into the model simulations.

• Journal of Industrial Convergence
• /
• v.18 no.1
• /
• pp.59-64
• /
• 2020

The effect of kinesio taping in patients with common peroneal nerve paralysis (PNP) have not been investigated. This purpose of this study was to evaluate the effects of kinesio taping on patients with common PNP. Ten subjects who had common PNP were included in this study. Kinesio taping was applied to the ankle joint (direction of dorsiflexion and eversion). The measurements were by manual muscle test (MMT; tibialis anterior, peroneus longus), active ROM (ankle dorsiflexion, eversion), pain (visual analogue scale (VAS), pressure pain threshold (PPT)), and balance (one leg standing). Subjects were assessed at baseline and 8 weeks of intervention. In the results, all subjects showed improvements in MMT, active ROM, Pain and balance at the 8-week. These findings are considered to be effective in applying kinesio taping on ankle joint in common PNP patients.

• Korean Journal of Veterinary Service
• /
• v.45 no.1
• /
• pp.63-69
• /
• 2022

Proliferative and necrotizing pneumonia (PNP) is a form of interstitial pneumonia that occurs in post-weaning pigs. In this study, we investigated the presence of swine influenza virus (SIV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2) and Aujeszky's disease virus (ADV) in PNP lesions in Jeju pigs. Based on the histopathologic criteria for PNP, a total of 50 cases were selected in Jeju pigs between 2008 and 2010. Coupled with histopathological examinations, the presence of ADV and SIV by polymerase chain reaction (PCR) and reverse transcription PCR (RT-PCR) and PRRSV and PCV2 by immunohistochemical (IHC) methods were investigated. Based on the PCR and RT-PCR methods, ADV and SIV nucleic acids were not detected in all cases. According to IHC, PRRSV was detected in 38 of the 50 cases examined (76%) and PCV2 in 25 cases (50%). PRRSV or PCV2 were detected in 19 (38%) or 6 (12%) cases, respectively. Both PRRSV and PCV2 were identified in other 19 cases (38%). Antigens of PRRSV and PCV2 were commonly observed in the cytoplasm of macrophages and clusters of necrotic cells in alveolar cavities. The results of the present study demonstrate that PRRSV is predominantly associated with PNP in Jeju pigs. Co-infection with PRRSV and PCV2 may enhance the severity of PNP lesions in affected pigs.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1998.11a
• /
• pp.151-154
• /
• 1998

기존의 바이폴라 논리회로에서 신호변환시 베이스 영역의 소수 캐리어를 빨리 제거하기 위해서, 베이스 부분의 매몰층을 줄여서 npn트랜지스터의 베이스와 에피층과 기판사이에 병합 pnp 트랜지스터를 생성한 트랜지스터와 게이트 당 전달 지연 시간을 측정하기 위한 링-발진기를 설계, 제작하였다. 게이트의 구조는 수직 npn 트랜지스터와 기판과 병합 pnp 트랜지스터이다. 결과로서 npn 트랜지스터의 에미터의 면적이 기존의 접합넓이에 비해서 상당히 적기 때문에 에미터에서 진성베이스로 유입되는 캐리어와 가장자리 부분으로 유입되는 캐리어가 상대적으로 많기 때문에 이 많은 양은 결국 베이스의 전류가 많이 헝성되며, 또 콜렉터의 매몰층이 거의 반으로 줄었기 때문에 콜렉터 전류가 적게 형성되어 이득이 낮아진다. 병합 pnp 트랜지스터는 베이스폭이 크고 농도 분포에서 에미터의 농도와 베이스의 농도 차이가 적기 때문에 전류 이득이 낮아졌다. 게이트를 연결하여 링-발진기를 제작하여 측정한 AC특성의 출력은 정현파로 논리전압의 진폭은 200mV, 최소 전달 지연시간은 211nS이며, 게이트당 최소 전달지연 시간은 7.26nS의 개선된 속도 특성을 얻었다.

• Korean Journal of Microbiology
• /
• v.29 no.3
• /
• pp.172-178
• /
• 1991

Intracellular purine nucleoside phosphorylase (PNP) from Saccharomyces cerevisiae was partially purified using ammonium sulfate fractionation, heat treatment, a DEAE-Sephadex A-50 anion exchange chromatography and a Sephadex G-100 gel filtration chromatography. The enzyme was purified 20 fold with 3% recovery. The stability of enzyme was kept by addition of inosine and dithiothreitol. The pH optimum was found to be from 6.3 to 7.3 PNP was sensitive to 10mM of $Hg^{2+}$ , $Cu^{2+}$ , and was inactivated completely by 2 mM of p-chloromercuribenzoate and 5,5'-dithiobis (2-nitrobenzoate). The enzyme was capable of catalyzing the phosphorolysis of inosine, deoxyinosine, guanosine, deoxyguanosine and adenosine.

• Journal of Microbiology
• /
• v.35 no.1
• /
• pp.15-20
• /
• 1997

Kinetic studies were done to elucidate the reaction mechanism of purine nucleoside phosphorylase (PNP) in Micrococcus Luteus. PNP catalyzes the reversible phosphorolysis of ribonucleosides to their respective base. The effect of alternative competing substrates suggested that a single enzyme was involved in binding to the active site for all purine nucleosides, inosine, deoxyiosine, guanosine, deoxyguanosine, adenosine and deoxyadenosine. Affinity studies showed that pentose moiety reduced the binding capacity and methylation of ring N-1 of inosine and guanosine had little effect on binding to bacterial enzyme, whereas these compounds did not bind to the mammalian enzymes. The initial velocity and product inhibition studies demonstrated that the predominant mechanism of reaction was an ordered bi, bi reaction. The nucleoside bound to the enzyme first, followed by phosphate. Ribose 1-phosphate was the first product to leave, followed by base.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.3
• /
• pp.96-106
• /
• 1996

One of the major problems for poly-Si TFTs is the large off state leakage current. LDD (lightly doped drain) and offset gated structures have been employed in order to reduce the leakage current. However, these structures also redcue the oN current significantly due to the extra series resistance caussed by the LDD or offset region. It is desirable to have a device which would have the properties of the offset gated structure in the OFF state, while behaving like a fully gated device in the oN state. Therefore, we propose a new thin film transistor with pnp junction gate which reduce the leakage curretn during the OFF state without sacrificing the ON current during the ON state.

• Nuclear Engineering and Technology
• /
• v.54 no.2
• /
• pp.501-506
• /
• 2022

Long turn-off time limits high frequency operation of Bipolar Junction Transistors (BJTs). Turn-off time decreases with increases in the recombination rate of minority carriers at switching transients. Fast neutron irradiation on a Si BJT incurs lattice damages owing to the displacement of silicon atoms. The lattice damages increase the recombination rate of injected holes with electrons, and decrease the hole lifetime in the base region of pnp Si BJT. Fast neutrons generated from a beryllium target with 30 MeV protons by an MC-50 cyclotron were irradiated onto pnp Si BJTs in experiment. The experimental results show that the turn-off time, including the storage time and fall time, decreases with increases in fast neutron fluence. Additionally, it is confirmed that the base current increases, and the collector current and base-to-collector current amplification ratio decrease due to fast neutron irradiation.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.25 no.5
• /
• pp.545-551
• /
• 2022

We proposed a design method for constant current pyro squib circuit. The current method using N MOSFET for the stability problem has a weakness of the current change, requiring a new design. This paper identified the problem with conventional squib circuit where the current is reduced by 25 % when maximum resistance is 3 ohms. Thus, we proposed a stable constant current driving circuit using P MOSFET and PNP BJT. We confirmed stable constant circuit operation through simulations and measurements of the proposed circuit design where the current did not change until the resistance reached 3 ohms.

• Microbiology and Biotechnology Letters
• /
• v.34 no.3
• /
• pp.211-215
• /
• 2006

AfsR2 is a global regulatory protein involved in the stimulation of secondary metabolite biosynthesis in various Streptomyces species including avermectin-producing S. avermitilis. Among several AfsR2-dependent genes identified from the comparative proteomics, the polyribonucleotide nucleotidyltransferase (PNP) and the glyceraldehyde-3-phosphate dehydrogenase (GPD) genes were previously proposed to regulate the actinorhodin production in S. lividans upon afsR2 over-expression positively and negatively, respectively. To show the biological significance of the PNP and GPD genes in the S. avermitilis strains, these two genes were functionally expressed in both the wild-type and the avermectin-overproducing mutant strains. The PNP gene expression stimulated secondary metabolite production in the wild-type S. avermitilis ATCC31267, but not in the avermectin-overproducing S. avermitilis ATCC31780. Interestingly, the GDP gene expression stimulated secondary metabolite production by 4-fold in the wild-type S. avermitilis ATCC31267 and by 2.5-fold in the avermectin-overproducing S. avermitilis ATCC31780, respectively. These results suggest that the biological significance of the afsR2-dependent PNP and GPD gene expressions on antibiotic biosynthetic regulation could be significantly different depending on Streptomyces species.