• Title/Summary/Keyword: selective cut-off

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Improvement of Step-charging Characteristic for Ni-MH Battery by Selective Cut-off Method (선택적 충전단계절환에 의한 Ni-MH 전지의 계단충전 특성 개선)

  • 안재영;강신영;김광헌;임영철
    • The Transactions of the Korean Institute of Power Electronics
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    • v.3 no.4
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    • pp.273-279
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    • 1998
  • In this paper, the proposed charging system consists of step charging mode and time-sharing equalization charging mode. As $\Delta$V=O point is detected, the proposed cut-off method will selectively cut off the only battery to reach the $\Delta$V=O point, preventing serial-connected batteries from undercharging. In the start of each step, the equalization charging mode is performed to reduce the capacity difference among the batteries. Though it is added to simple circuit for selective cut-off, comparing with recently used step-charging method, this system can improve the life cycle of battery and charging efficiency, and be also very effective for preventing the batteries from overcharging and undercharging.

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Transbilayer Effects of n-Alkanols on the Fluidity of Phospholipid Model Membranes

  • Yun, Il;Kang, Jung-Sook
    • Archives of Pharmacal Research
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    • v.15 no.2
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    • pp.152-161
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    • 1992
  • Selective quenching of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of model membranes of phospholipids (SPMVPL) extracted from synaptosomal plasma membrane vesicles (SPMV). The polarization (P), anisotropy (r), limiting anisotropy $(r_\infty$), and order parameter (S) of DPH in the inner monolayer were 0.019, 0.014, 0.018, and 0.047, respectively, greater than calculated for the outer monolayer of SPMVPL. Selective quenching of DPH by trinitrophenyl groups was also utilized to examine the effects of n-alkanols on the individual monolayer structure of SPMVPL. n-Alkanols fluidized the hydrocarbon region of bulk SPMVPL and the potencies of n-alkanols up to 1-nonanon increased with carbon chain length. It appears that the potencies in bilayer fluidization increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity. The n-alkanols had greater fluidizing effects on the outer monolayer as compared to the inner monolayer of SPMVPL, even though these selective effects tended to become weaker as the carbon chain length increased. Thus, it has been proven that n-alkanols exhibit selective rather than nonselective fludizing effects within transbilayer domains of SPMVPL.

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Knee extension test for assessing hamstring flexibility (넓적다리뒤근육의 유연성 측정을 위한 무릎폄 검사)

  • Wootaek Lim
    • Journal of Korean Physical Therapy Science
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    • v.30 no.1
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    • pp.31-40
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    • 2023
  • Hamstring flexibility is an important factor that affects muscle performance of the lower extremities and is closely associated with sports injuries. Therefore, evaluation of flexibility is important in clinical practice. Results of evaluation are determined by types of tests and cut-off values used; therefore, accurate and detailed understanding of these is necessary before examination. Although the straight leg raise and sit and reach tests are used to evaluate hamstring extensibility, structures including the nerves, fascia, and other muscles can significantly confound the results of these tests. The knee extension test is performed at 90° of hip flexion to minimize the posterior pelvic tilt that occurs during the straight leg test. The knee extension test is most recommended for selective evaluation of hamstring flexibility. The knee extension test is classified into active and passive tests. The cut-off value is usually set at 20° for the active and at 10° for the passive knee extension test. Although a strong association is observed between the two tests, the active knee extension test is preferred in clinical practice because it can be performed by a single examiner, which serves as an advantage. Age, sex, and warm-up exercise tend to affect flexibility; therefore, results should be interpreted with caution. Detailed understanding of each flexibility test is important for reliable evaluation.

Transbilayer Effects of n-Alkanols on the Fluidity of Model Membranes of Total Lipids Extracted from Synaptosomal Plasma Membrane Vesicles (n-Alkanols가 소의 대뇌피질 Synaptosomal Plasma Membrane Vesicles로부터 추출 제제한 총지질 인공세포막 이중층간에 형성된 비대칭적 유동성에 미치는 비대칭적 영향)

  • Yun, Il;Kang, Jung-Sook
    • The Korean Journal of Pharmacology
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    • v.28 no.2
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    • pp.191-199
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    • 1992
  • Selective quenching of 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of model membranes of total lipids (SPMVTL) extracted from synaptosomal plasma membrane vesicles (SPMV). The polarization (P), anisotropy (r), limiting anisotropy $(r_{\infty})$, and order parameter (S) of DPH in the inner monolayer were 0.031, 0.025, 0.033, and 0.070, respectively, greater than calculated for the outer monolayer of SPMVTL. Selective quenching of DPH by trinitrophenyl groups was also utilized to examine the effects of n-alkanols on the individual monolayer structure of SPMVTL. n-Alkanols fluidized the hydrocarbon region of bulk SPMVTL, and the potencies of n-alkanols up to 1-nonanol increased with carbon chain length. It appears that the potencies in bilayer fluidization increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity. The n-alkanols had greater fluidizing effects on the outer monolayer as compared to the inner monolayer of SPMVTL, even though these selective effects tended to become weaker as carbon chain length increased. Thus, it has been proven that n-alkanols exhibit selective rather than nonselective fluidizing effects within transbilayer domains of SPMVTL.

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A Novel Bottom-Gate Poly-Si Thin Film Transistors with High ON/OFF Current Ratio (ON/OFF 전류비를 향상시킨 새로운 bottom-gate 구조의 다결정 실리콘 박막 트랜지스터)

  • Jeon, Jae-Hong;Choe, Gwon-Yeong;Park, Gi-Chan;Han, Min-Gu
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.315-318
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    • 1999
  • We have proposed and fabricated the new bottom-gated polycrystalline silicon (poly-Si) thin film transistor (TFT) with a partial amorphous-Si region by employing the selective laser annealing. The channel layer of the proposed TFTs is composed of poly-Si region in the center and a-Si region in the edge. The TEM image shows that the local a-Si region is successfully fabricated by the effective cut out of the incident laser light in the upper a-Si layer. Our experimental results show that the ON/OFF current ratio is increased significantly by more than three orders in the new poly-Si TFT compared with conventional poly-Si TFT. The leakage current is decreased significantly due to the highly resistive a-Si re TFTs while the ON-series resistance of the local a-Si is reduced significantly due to the considerable inducement of electron carriers by the positive gate bias, so that the ON-current is not decreased much.

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A Proposal for Optical Diagnostics Through the Enhancement of Diffraction Patterns Using Thin-film Interference Filters

  • Stefanita Carmen Gabriela;Shao Yun Feng
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.6
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    • pp.428-434
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    • 2004
  • Coarse clumping of solid materials within diseased biological cells can have a marked influence on the light scattering pattern. Perturbations in refractive index lead to distinct varia­tions in the cytometric signature, especially apparent over wide scattering angles. The large dynamic range of scattering intensities restricts collection of data to narrow angular intervals be­lieved to have the highest potential for medical diagnosis. We propose the use of an interfer­ence filter to reduce the dynamic range. Selective attenuation of scattering intensity levels is expected to allow simultaneous data collection over a wide angular interval. The calculated angu­lar transmittance of a commercial shortwave-pass filter of cut-off wavelength 580 nm indicates significant attenuation of scattering peaks below ${\~}\;10^{circ}$, and reasonable peak equalization at higher angles. For the three-dimensional calculation of laser light scattered by cells we use a spectral method code that models cells as spatially varying dielectrics, stationary in time. How­ever, we perform preliminary experimental testing with the interference filter on polystyrene microspheres instead of biological cells. A microfluidic toolkit is used for the manipulation of the microspheres. The paper intends to illustrate the principle of a light scattering detection system incorporating an interference filter for selective attenuation of scattering peaks.

Characterization of Desalination on the Boiled Extract of Baby Neck Clam(Tapes variegata) by Electrodialysis (전기투석기를 이용한 바지락 자숙액의 탈염 특성)

  • 박표잠;이상훈;김세권
    • Membrane Journal
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    • v.10 no.2
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    • pp.92-101
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    • 2000
  • For selective elimination of salt in the boiled extract of baby neck clam (Tapes variegata, BEBNC), electrodialyzer was used and the desalination conditions of BEBNC were determined at various concentrations, pH's and volumes of BEBNC. The ion-exchange membrane with a molecular weight cut off 100 Da was used for desalting of BEBNC. The desalination times on BEBNC concentrations of 0.5% and 4% were 100 min and 170 min and the final desalting ratio was above 90%. 1'he desalination of BEBNC at pH 4.0 was 12% higher than that at pH 9.0 for 60 min. The electrodialysis process could remove above 90% of the initial salt content in 2% BEBNC of 1 L for 80 min. The results obtained prove that electrodialysis is a practical solution to the problem of selective elimination of salt from BEBNC.

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Dynamics of spermatial nuclei in trichogyne of the red alga Bostrychia moritziana (Florideophyceae)

  • Shim, Eunyoung;Park, Hana;Im, Soo Hyun;Zuccarello, Giuseppe C.;Kim, Gwang Hoon
    • ALGAE
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    • v.35 no.4
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    • pp.389-404
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    • 2020
  • Red algal fertilization is unusual and offers a different model to the mechanism of intracellular transport of nuclei and polyspermy blocking. A female carpogonium (egg) undergoes plasmogamy with many spermatia (sperm) simultaneously at the receptive structure, trichogyne, which often contains numerous male nuclei. The pattern of selective transport of a male nucleus to the female nucleus, located in the cell body of the carpogonium, remain largely unknown. We tracked the movement of spermatial nuclei and cell organelles in the trichogyne after plasmogamy using time-lapse videography and fluorescent probes. The fertilization process of Bostrychia moritziana is composed of five distinctive stages: 1) gamete-gamete binding; 2) mitosis in the attached spermatia; 3) formation of a fertilization channel; 4) migration of spermatial nuclei into the trichogyne; and 5) cutting off of the trichogyne cytoplasm from the rest of the cell after karyogamy. Our results showed that actin microfilaments were involved in the above steps of fertilization, microtubules are involved only in spermatial mitosis. Time-lapse videography showed that the first ("primary") nucleus which entered to trichogyne moved quickly to the base of carpogonium and fused with the female nucleus. The transport of the primary male nucleus to the egg nucleus was complete before its second nucleus migrated into the trichogyne. Male nuclei from other spermatia stopped directional movement soon after the first one entered the carpogonial base and oscillated near where they entered trichogyne. The cytoplasm of the trichogyne was cut off at a narrow neck connecting the trichogyne and carpogonial base after gamete nuclear fusion but gamete binding and plasmogamy continued on the trichogyne. Spermatial organelles, including mitochondria, entered the trichogyne together with the nuclei but did not show any directional movement and remained close to where they entered. These results suggest that polyspermy blocking in B. moritziana is achieved by the selective and rapid transport of the first nucleus entered trichogyne and the rupture of the trichogyne after gamete karyogamy.

Hemolytic Activity of Culture Supernatant of Xenorhabdus nematophilus, a Symbiotic Bacterium of Entomopathogenic Nematodes

  • Ryu, Keun-Garp;Bae, Jun-Sung;Kwack, Kyu-Bum;Kwon, O-Yul;Park, Sun-Ho
    • Journal of Microbiology and Biotechnology
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    • v.12 no.3
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    • pp.526-529
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    • 2002
  • Lysis of erythrocytes isolated from human, rabbit, and mouse blood samples was investigated with the culture supernatant of Xenorhabdus nematophilus in a primary form. Prior to use, the culture supernatant of the bacteria was concentrated and the concentrate was dialyzed against Tris-HCl buffer (10 mM, pH 8.1) by ultrafiltration using PM-5 membrane with a molecular weight cut-off of 5,000. At $30^{\circ}C$, the supernatant exhibited no lytic activity towards three types of erythrocytes. However, at $4^{\circ}C$, the supernatant showed selective lytic activity towards rabbit erythrocytes within 90 min. yet did not lyze human or mouse erythrocytes. Microscopic examination clearly revealed that most of the rabbit erythrocytes had been fumed into ghost forms.

Fabrication and characterization of the SiGe HBTs using an RPCVD (RPCVD를 이용한 실리콘 게르마늄 이종 접합 바이폴라 트랜지스터 제작 및 특성 분석)

  • 한태현;서광열
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.8
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    • pp.823-829
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    • 2004
  • In this paper, non-self-aligned SiGe HBTs with ${f}_\tau$ and${f}_max $above 50 GHz have been fabricated using an RPCVD(Reduced Pressure Chemical Vapor Deposition) system for wireless applications. In the proposed structure, in-situ boron doped selective epitaxial growth(BDSEG) and TiSi$_2$ were used for the base electrode to reduce base resistance and in-situ phosphorus doped polysilicon was used for the emitter electrode to reduce emitter resistance. SiGe base profiles and collector design methodology to increase ${f}_\tau$ and${f}_max $ are discussed in detail. Two SiGe HBTs with the collector-emitter breakdown voltages ${BV}_CEO$ of 3 V and 6 V were fabricated using SIC(selective ion-implanted collector) implantation. Fabricated SiGe HBTs have a current gain of 265 ∼ 285 and Early voltage of 102 ∼ 120 V, respectively. For the $1\times{8}_\mu{m}^2$ emitter, a SiGe HBT with ${BV}_CEO$= 6 V shows a cut-off frequency, ${f}_\tau$of 24.3 GHz and a maximum oscillation frequency, ${f}_max $of 47.6 GHz at $I_c$of 3.7 mA and$V_CE$ of 4 V. A SiGe HBT with ${BV}_CEO$ = 3 V shows ${f}_\tau$of 50.8 GHz and ${f}_max $ of 52.2 GHz at $I_c$ of 14.7 mA and $V_CE$ of 2 V.