• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1005-1009
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• 2001

The application of the ultrasonic nozzle has been extended because it is possible atomization of liquid material. In this study, the driving characteristics of the ultrasonic nozzle on the driving circuit were investigated. And the characteristics of the ceramic oscillator were investigated for the temperature stability. The ceramic oscillator were made the Pb[(Sb$\sub$1/2/,Nb$\sub$1/2/)$\sub$0.035/-(Mn$\sub$1/3/Nb$\sub$2/3/)$\sub$0.065/- (Zr$\sub$x/Ti$\sub$l-x/)$\sub$0.9/]O$_3$with mole ratio of Zr/Ti. The ceramis oscillator were need the curie temperature of the over 300[$^{\circ}C$] for the temperature stability. When the Zr/Ti ratio was 49/51, it's curie temperature is 322[$^{\circ}C$] and the electromechanical coupling factor(k$\sub$p/) and mechanical quality factor(Q$\sub$m/) showed the values of 0.555, 1,214, respectively The resonance frequency of ceramic oscillator were from 40KHz to 45KHz. So that, the driving circuit were made a possibility that the frequency are variable. The driving current of ultrasonic nozzle showed the value of maximum 80[mA]. Also, The surface temperature of ceramic oscillator showed 80[$^{\circ}C$] at driving time 10[min]. We knew that the ultrasonic nozzle had stabile driving above 10[min.].

• Wind and Structures
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• v.18 no.1
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• pp.57-67
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• 2014

For a building with a dominant windward wall opening, the wind-induced internal pressure response can be described by a second-order non-linear differential equation. However, there are two ill-defined parameters in the governing equation: the inertial coefficient $C_I$ and the loss coefficient $C_L$. Lack of knowledge of these two parameters restricts the practical use of the governing equation. This study was primarily focused on finding an accurate reference value for $C_I$, and the paper presents a systematic investigation of the factors influencing the inertial coefficient for a wind-tunnel model building including: opening configuration and location, wind speed and direction, approaching flow turbulence, the model material, and the installation method. A numerical model was used to simulate the volume deformation under internal pressure, and to predict the bulk modulus of an experimental model. In considering the structural flexibility, an alternative approach was proposed to ensure accurate internal volume distortions, so that similarity of internal pressure responses between model-scale and full-scale building was maintained. The research showed 0.8 to be a reasonable standard value for the inertial coefficient.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.86-86
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• 1997

Human annexin I is a member of annexin family of calcium dependent phospholipid binding proteins, which have been implicated in various physiological roles including phospholipase A$_2$ (PLA$_2$) inhibition, membrane fusion and calcium channel activity. In this work, the structure of N-terminally truncated human annexin I (Δ-annexin I) and its interactions with Ca$\^$2+/, ATP and cAMP were studied at atomic level by using $^1$H, $\^$15/N, $\^$l3/C NMR (nuclear magnetic resonance) spectroscopy. The effect of Ca$\^$2+/ binding on the structure of Δ-annexin I was investigated, and compared with that of Mg$\^$2+/ binding. The addition of Ca$\^$2+/ to Δ-annexin I caused some changes in the high field and low field regions of $^1$H NMR spectra. Whereas, upon addition of Mg$\^$2+/ to Δ-annexin I, almost no change could be observed. Also we found that the binding ratio of ATP to Δ-annexin I is 1. Because Δ-annexin I is a large protein with 35 kDa molecular weight, site-specific (carbonyl-$\^$l3/C, amide-$\^$15/N) labeling technique was used to determine the interaction sites of Δ-annexin I with Ca$\^$2+/ and ATP. Assignments of all the histidinyl carbonyl carbon resonances have been completed by using Δ-annexin I along with its specific 1,2-subdomain. The carbonyl carbon resonances originating from His52 and His246 of Δ-annexin I were significantly affected by Ca$\^$2+/ binding, and some Tyr and Phe resonances were also affected. The carbonyl carbon resonances originating from His52 is significantly affected by ATP binding, therefore His52 seems to be involved in the ATP binding site of Δ-annexin I.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1723-1725
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• 1999

This paper is the study for piezoelectric properties of PMN-PT-PZ composition for high power piezoelectric device. It needs the properties such as high mechanical quality factor(Qm), high electromechanical coupling coefficient(kp) and high dielectric strain constant$(d_31)$, and the stable electromechanical properties under high vibration level. For acquiring this results, the value of x is changed in 0.1Pb$(Mn_{1/3}Nb_{2/3})O_3$+(0.9-x)$PbZrO_3+xPbTiO_3$ composition to find MPB(morphotropic phase boundary), and the piezoelectric constants is measured by resonance-antiresonance frequency method, based on IRE Standard. Also, it is measured as a function of the amount of additive, $Nb_2O_5$. When the composition is applied to high power device, the electromechanical properties is measured by laser vibrometer to confirm the reliablity under high vibration level. From these results, PMN-PT-PZ composition is shown excellent properties and capacity of application to high power device.

• YAKHAK HOEJI
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• v.43 no.3
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• pp.369-377
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• 1999

A new series of highly water soluble platinum(II) complexes {Pt(II)[1,3-bis(phenylthio) propane](trans- -1,2-diaminocyclohexane) (PC-1) and Pt(II)[1,3-bis-(phenythio)propane] cis-1,2-diaminocyclohexane(PC-2)} were synthesized, and characterized by their elemental analysis and by various spectroscopic techniques[infrared(IR), 13C-nuclear magnetic resonance (NMR)]. In vitro antitumor activity of new Pt(II) complexes was tested against P-388 and L-1210 mouse lymphocytic leukemia cell lines, PC-14 / P, PC-14/ADM and PC-14 / CDDP human pulmonary adenocarcinima, DU-145 human prostate carcinoma, HT-1376 human bladder carcinoma, ZR-75-1 human breast carcinoma, MKN-45/P and MKN-45/CDDP human gastric adenocarcinoma cell lines using colorimetric MTT[3-(4,5-dimethyl thiazol-2-yl)-2.5-diphenyltetrazoliumbromide] assay for cell survival and proliferation. PC-1 showed active against L-1210, P-388 leukemia, human lung, stomach, prostate, bladder and breast cancer cell lines, and the antitumor activity of these compounds were comparable or superior to those of PC-2 and displatin. The nephrotoxicities of PC-1 and PC-2 were found quite less than that of cisplatin using MTT and [3H] thymidine uptake in rabbit proximal tubule cells and human kidney cortical cells. Based on these results, this novel platinum (II) complex compound (PC-1) represents a valuable lead in the development of a new anticancer chemotherapeutic agent capable of improving antitumor activity and low nephrotoxicity.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.118-124
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• 2017

Brain abscess commonly occurs secondary to an adjacent infection (mostly in the middle ear or paranasal sinuses) or due to hematogenous spread from a distant infection or trauma. Pulmonary arteriovenous fistulas (AVFs) are abnormal direct communications between the pulmonary artery and vein. We present two cases of brain abscess associated with asymptomatic pulmonary AVF. A 65-year-old woman was admitted with a headache and cognitive impairment that aggravated 10 days prior. An magnetic resonance (MR) imaging revealed a brain abscess with severe edema in the right frontal lobe. We performed a craniotomy and abscess removal. Bacteriological culture proved negative. Her chest computed tomography (CT) showed multiple AVFs. Therapeutic embolization of multiple pulmonary AVFs was performed and antibiotics were administered for 8 weeks. A 45-year-old woman presented with a 7-day history of progressive left hemiparesis. She had no remarkable past medical history or family history. On admission, blood examination showed a white blood cell count of 6290 cells/uL and a high sensitive C-reactive protein of 2.62 mg/L. CT and MR imaging with MR spectroscopy revealed an enhancing lesion involving the right motor and sensory cortex with marked perilesional edema that suggested a brain abscess. A chest CT revealed a pulmonary AVF in the right upper lung. The pulmonary AVF was obliterated with embolization. There needs to consider pulmonary AVF as an etiology of cerebral abscess when routine investigations fail to detect a source.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.496-499
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• 1995

Amorphous $Co_{80+x}TM_{12}B_{8-x}$ (TM = Ti, Zr, Hf, Nb and x = 0, 2, 4 at%) alloys were prepared by single roll melt spinning technique. Saturation magnetization of the amorphous ribbons was measured by SQUID and vibrating sample magnetometer from 5 to 800 K under applied fields up to 10 kOe. Typical thermo-magnetization curves were observed and the average values of the spectroscopic splitting g factor were estimated from the ferromagnetic resonance curve. For all the amorphous alloys studied here the saturation magnetization in the temperature range 5 K up to about $0.3T_{c}$ can be described by the Bloch relation: $M_{s}(T)\;=\;M_{s}(0)(1-BT^{3/2}-CT^{5/2})$. From the values of $M_{s}(0)$, B and spectroscopic splitting g factor the spin wave stiffness constants were calculated.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.4
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• pp.415-421
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• 2014

In this paper, reactorless high efficiency boost DC/DC converter for EV is proposed. In proposed converter, improves efficiency because decrease power loss when the switches are turned on/off using zero current switching (ZCS) at all switch of primary full bridge. By replacing reactance ingredients of L-C resonance circuit for ZCS with leakage inductance ingredients of high frequency transformer, it reduces system size and expense because of not add special reactor. For validity verification of proposed converter, in the paper implements simulation using PSIM and perform experiment by making 5KW DC/DC converter. In experimental results, efficiency of proposed converter conformed superiority.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.117-120
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• 2010

A novel stepped-patch loaded coplanar waveguide(SPLCPW) structure is proposed and applied to the design of a low-pass filter(LPF). The stepped-patch loaded on the opposite side of the CPW plane is shown to provide a shunt-connected series L-C resonance, which is dual to that of a conventional CPW defected ground structure(DGS). As a simple example of the proposed SPLCPW circuit, a 3-pole SPLCPW LPF is designed and good results are obtained.

• Journal of the Korean Society of Safety
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• v.14 no.4
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• pp.100-107
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• 1999

The purpose of the study is to investigate the effect of H$_2$ pressure on partial discharge (PD) activity and aging rate in turbine generator winding insulations. A series of field tests and laboratory tests were peformed to investigate the effect of $H_2$ pressure on PD activity. Field tests were conducted at two unit turbine generators in two conditions, in $H_2$ pressure and in air atmosphere. Obtained results are as follows ; 1) ${\Delta}tan{\delta}$ and maximum partial discharge are reduced with increase of $H_2$ pressure and partial discharge inception voltage. 2) The reduction ratio of ${\Delta}tan{\delta}$ due to $H_2$ pressure is higher than one of PD magnitude. 3) Partial discharge pulses suffer from attenuation and distortion when transmitted along windings, because of the complex L-C network between windings. From the result, partial discharge pulses are subjected to resonance phenomena in a generator winding.