• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.61-63
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• 1962

The polarographic behaviors of Tl(I) was investigated in EDTA and NTA as supporting electrolytes for determination of Tl(I). A base solution containing 0.005 % gelatine, 0.1 M EDTA, and 0.05 M NTA was used. The halfwave potential of Tl(I) determined is -0.495 V v.s. S.C.E. in 0.1 M EDTA at pH 4.1 and -0.520V v.s. S.C.E. in 0.05 M NTA at pH 6.3. In this paper, the effects of gelatine concentration and pH values was investigated. The half-wave potentials of common elements was determined and compared with the half-wave potential of Tl(I).

• Honam Mathematical Journal
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• v.40 no.3
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• pp.549-559
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• 2018

In this paper, we consider the congruences involving harmonic numbers and the terms of the sequences {$U_{kn}$} and {$V_{kn}$}. For example, for an odd prime number p, $${\sum\limits_{i=1}^{p-1}}H_i{\frac{U_{k(i+m)}}{V^i_k}}{\equiv}{\frac{(-1)^kU_{k(m+1)}}{_pV^{p-1}_k}}(V^p_k-V_{kp})(mod\;p)$$, where $m{\in}{\mathbb{Z}}$ and $k{\in}{\mathbb{Z}}$ with $p{\nmid}V_k$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.115-120
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• 1972

The data Presented in this Paper, on the body and Jumping voltage of Penaeus japonicus BATE, are part of a current study on shrimp behaviour in order to improve fishing efficiency of the fishing gear. The experiments concerning electrical stimuli was mostly carried out at the Marine Laboratory of Busan Fisheries College in 1972. The following are the results obtained from the present investigations : 1. When the voltages between a pair of electrodes were fixed constant, the voltage drops between them showed almost constant electrical field. 2. Threshold voltages of the animals varied with body direction to the electrical field, i. e., 200 -500 mV for parallel, 500-1400 mV for vertical and 300-800 mV for diagonal ($45^{\circ}$) settings. 3. Jumping voltages of the animals also varied with the body direction to the electrical field; i. e., 250-1000 mV for parallel, 800-2500 mV for vertical and 400-1300 mV for diagonal settings. 4. The shrimp, in general, were more sensitive to the electrical stimuli when oriented to the cathode rather than the anode. 5. Jumping voltages decreased when the interrupted current was applied to the animals, i. e., less than 200 mV for paralled and 500mV for vertical direction of the body to the electrical field.

• Journal of The Korean Astronomical Society
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• v.28 no.1
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• pp.31-43
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• 1995

We present UBVRI CCD photometry of the Type Ie supernova SN 19941 in M51 which was discovered on April 2, 1994 (UT). UBVRI CCD photometry of SN 1994 I were obtained for the period of the first two months from April 4, 1994, using the Seoul National University Observatory 60 cm telescope. The light curves of SN 19941 show several interesting features: (a) SN 19941 reaches the maximum brightness at B-band on April 8.23 (B = 13.68 mag), at V-band on April 9.10 (V = 12.89 mag), and at I-band on April 10.32 (I = 12.48 mag); (b) The light curves around the maximum brightness are much narrower than those of other types of supernovae; (c) The light curves after the peak decline more steeply than those of other types of supernovae; and (d) The colors get redder from $(V-R){\approx}0.2 mag ((V - I){\approx} 0.3 mag, (B - V){\approx}0.7 mag)$ on April 4 to $(V-R){\approx}0.6 mag ((V-1){\approx}0.9 mag, (B-V){\approx}1.3 mag)$ on April 18. Afterwards (V - R) colors get bluer slightly $(by\~0.005 mag/day)$, while (V-I) colors stay almost constant around $(V-1){\approx}1.0 mag$. The color at the maximum brightness is (B-V)=0.9 mag, which is $\~1$mag redder than the mean color of typical Type la supernovae at the maximum brightness. The light curves of SN 1994I are similar to those of the Type Ie supernova SN 1962L in NGC 1073. Adopting the distance modulus of $(m-M)_0 = 29.2 mag$ and the reddening of E(B - V) = 0.45 mag [Iwamoto et al. 1994, preprint for ApJ], we derive absolute magnitudes at the maximum brightness of SN 1994I, Mv(max) = -17.7 mag and MB(max) = -17.4 mag. This result shows that SN 1994I was $\~2$mag fainter at the maximum brightness compared with typical Type Ia supernovae. A narrower peak and faster decline after the maximum in the light curve of SN 1994I compared with other types of supernovae indicate that the progenitor of SN 1994I might be a lower mass star compared with those of other types of supernovae.

• The Korean Journal of Physiology
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• v.17 no.1
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• pp.1-11
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• 1983

1) The two microelectrode method was used to voltage clamp small preparations of rabbit sinoatrial node. The kinetics of hyperpolarization activated inward current, $i_f$ were analysed. 2) The hrperpolarization pulses activated $i_f$ current in the presence of $10^{-7}g/ml$ TTX and 2 mM $Mn^{2+}$. The activation range was in between -45 mV to -75 mV. The current magnitude was increased and time course was faster by strong hyperpolarization pulses. 3) Standard envelope tests indicated that this current is exponentially controlled by single gate. 4) Semilogarithmic plot of $i_f$ activation versus time was found to be linear in the activation range. The decrease in current magnitude and the shifts in activation curve and rate constants curve to the hyperpolarizing direction were obtained with $Ba^{2+}$, indicating that $Ba^{2+}$ shifts the voltage dependence of the gating kinetics, were partially reversed by 24 mM $K^+$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.6 s.360
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• pp.19-27
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• 2007

This paper presents power supply-insensitive Gbps low power LVDS I/O circuits. The proposed LVDS I/O has been designed and simulated using 1.8V, $0.18\;{\mu}m$ TSMC CMOS Process. The LVDS I/O includes transmitter and receiver parts. The transmitter circuits consist of a differential phase splitter and an output stage with the switched capacitor common mode feedback(SC-CMFB). The differential phase splitter generates a pair of differential signals which provides a balanced duty $cycle(50{\pm}2%)$ and phase difference$(180{\pm}0.2^{\circ})$ over a wide supply voltage range. Also, $V_{OD}$ voltage is 250 mV which is the smallest value of the permissible $V_{OD}$ range for low power operation. The output buffer maintains the required $V_{CM}$ within the permissible range$(1.2{\pm}0.1V)$ due to the SC-CMFB. The receiver covers a wide input DC offset $range(0.2{\sim}2.6\;V)$ with 38 mV hysteresis and Produces a rail-to-rail output over a wide supply voltage range. Beside, the designed receiver has 38.9 dB gain at 1 GHz, which is higher than conventional receivers.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.265-266
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• 2015

A search for luminous white dwarfs (WDs) in several nearby Galactic globular clusters (GCs) was carried out using the deep and homogeneous photometric catalog of Galactic GCs taken with the ACS/WFC aboard the Hubble Space Telescope (HST) by Sarajedini et al. and Anderson et al- It resulted in the identification of luminous WD candidates in the GCs M13 (NGC 6205) and M22 (NGC 6656). The purpose of the present study is to identify luminous WDs in the deep and homogeneous V versus V - I color-magnitude diagrams (CMDs) of several nearby Galactic GCs taken with the ACS/WFC aboard the HST. Using photometric data for the GCs M13 and M22 that are now in the public domain, the V versus V - I CMDs of the GCs M13 and M22 were constructed. Many spurious detections in the CMDs were removed using the photometric quality parameters qfit(V) and qfit(I), and a radial restriction was applied to the CMDs to remove the central stars with higher photometric errors due to central crowding. From each resultant V versus V - I CMD of the GCs M13 and M22, a dozen or so luminous WD candidates were identified. They were confirmed as stellar objects in the accompanying ACS/WFC images and their positions in the CMDs were in the bright part of the DA WD cooling curve. Therefore, the luminous WD candidates in the GCs M13 and M22 seem to be true luminous WDs, and spectroscopic observations are needed to confirm their true identity.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.169-183
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• 1997

We have investigated the two types of voltage-dependent outward potassium (K) currents, i.e. delayed rectifier K current ($I_{K(V)}$) and 'A-like' transient outward K current ($I_{to}$) with patch-clamp technique in single smooth muscle cells (SMCs) isolated from rabbit basilar artery, and investigated the characteristics of them. The time-courses of activation were well fitted by exponential function raised to second power ($n^2$) in $I_{K(V)}$ and fourth power ($n^4$) in $I_{to}$. The activation, inactivation and recovery time courses of $I_{to}$ were much faster than that of $I_{K(V)}$. The steady-state activation and inactivation of $I_{K(V)}$ was at the more hyperpolarized range than that of $I_{to}$ contrary to the reports in other vascular SMCs. Tetraethylammonium chloride (TEA; 10 mM) markedly inhibited $I_{K(V)}$ but little affected $I_{to}$. 4-Aminopyridine (4-AP) had similar inhibitory potency on both currents. While a low concentration of $Cd^{2+}$ (0.5 mM) shifted the current- voltage relationship of $I_{to}$ to the positive direction without change of maximum conductance, $Cd^{2+}$ did not cause any appreciable change for $I_{K(V)}$.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.32.1-32.13
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• 2020

Levofloxacin pharmacokinetic profiles were evaluated in 6 healthy female rabbits after intravenous (I/V), intramuscular (I/M), or subcutaneous (S/C) administration routes at a single dose of 5 mg/kg in a 3 × 3 cross-over study. Plasma levofloxacin concentrations were detected using a validated Ultra Performance Liquid Chromatography method with a fluorescence detector. Levofloxacin was quantifiable up to 10 h post-drug administration. Mean AUC_0-last values of 9.03 ± 2.66, 9.07 ± 1.80, and 9.28 ± 1.56 mg/h^*L were obtained via I/V, I/M, and S/C, respectively. Plasma clearance was 0.6 mL/g*h after I/V administration. Peak plasma concentrations using the I/M and S/C routes were 3.33 ± 0.39 and 2.91 ± 0.56 ㎍/mL. Bioavailability values, after extravascular administration were complete, - 105% ± 27% (I/M) and 118% ± 40% (S/C). Average extraction ratio of levofloxacin after I/V administration was 7%. Additionally, levofloxacin administration effects on tear production and osmolarity were evaluated. Tear osmolarity decreased within 48 h post-drug administration. All 3 levofloxacin administration routes produced similar pharmacokinetic profiles. The studied dose is unlikely to be effective in rabbits; however, it was calculated that a daily dose of 29 mg/kg appears effective for I/V administration for pathogens with MIC < 0.5 ㎍/mL.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.41.1-41.1
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• 2015

허블우주망원경에 장착된 ACS/WFC로 획득한 Anderson 등과 Sarajedini 등의 깊고 균질한 VI 측광 목록을 이용하여 우리은하 구상성단 M13(NGC 6205)과 M22(NGC 6656)의 뜨겁고 밝은 백색왜성 탐사를 수행하였다. 허블우주망원경 VI 측광 목록으로부터 M13과 M22의 V 대 V-I 색-등급도를 작성하였고 여기에서 많은 항성으로 잘못 검출된 대상(spurious detection)을 측광 질매개변수 qfit(V)와 qfit(I)에 따라서 제거하였다. 그리고 M13의 경우에는 중심의 높은 밀집도에 기인한 높은 측광오차를 가진 중심영역 별을 제거하기 위하여 성단 중심으로부터의 추가적인 반경 제한을 실시하였다. 이렇게 도출한 M13과 M22의 각각의 V 대 V-I 색-등급도에서 십여개 정도의 백색왜성 후보를 동정하였다. 이들은 동반되어 제공되는 ACS/WFC 각각의 영상에서 항성체로 동정되었으며, M13과 M22의 성단 중심부 영역에 임의적으로 분포하고 있으며, 색-등급도상의 위치가 DA 백색왜성 냉각계열의 밝은 부분에 위치하고 있어서 이들이 M13과 M22의 진짜 백색왜성임을 나타내고 있다. 이들에 대해 추가적으로 분광학적인 관측 연구를 수행한다면 이들의 백색왜성 진위 여부와 다양한 물리량을 밝혀낼 것이다. 또한 가까운 구상성단에 대해서 같은 방법으로 조사를 수행하면 더 많은 구상성단에서 갓 태어난 뜨겁고 밝은 백색왜성을 찾아낼 것으로 기대한다.