• The Journal of Korean Obstetrics and Gynecology
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• v.26 no.4
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• pp.48-65
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• 2013

Objectives: We took breast milk samples and analyzed them using HPLC and LC/MS/MS, to evaluate the effects of taking Saenghwa-tang during breastfeeding on breast milk. Methods: The study participants were 20 lactating women who admitted in Korean medical postpartum care center. Breast milks were collected from paticipants who have been administrated Saenghwa-tang for more than 3 days. We used HPLC and LC/MS/MS for the determinations of amygdalin, liquiritins, 6-gingerol, decursin and decursinol angelate in Saenghwa-tang. Results: 1. Participants' $Mean{\pm}S.D$ (standard deviation) of age is $31.05{\pm}1.96$, and 15 participants had normal delivery and 5 participants had cesarean delivery. 12 participants were primipara and 8 participants were multipara. $Mean{\pm}S.D$ of lactating date is $9.4{\pm}0.94$. 2. Using HPLC, we learned LOQ level peak that matches the peak retention time of standard components of Saenghwa-tang was not detected from 20 breast milk samples. 3. Using LC/MS/MS, decursin of Angelicae Gigantis Radix was detected from HMSP 02, HMSP 04, HMSP 06, HMSP 11, and the each concentrations are 16, 2, 64, 11 ppb. Liquiritin of Glycyrrhizae Radix was not detected from HMSP 13~HMSP 18. Conclusions: Data obtained by this approach shows that this method is reliable and suitable for determining the safety of taking Saenghwa-tang during breastfeeding.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.267.1-267.1
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• 2016

본 연구에서는 nematic 액정의 종류 중 하나인 5CB (4-Cyano-4'-pentylbiphenyl) 물질을 박막 트랜지스터 (TFT)의 passivation 층으로 사용했을 때 그 전기적 특성향상을 확인하였다. RF-magnetron sputtering법으로 증착된 비정질 InGaZnO 박막을 활성층으로 사용한 TFT를 제작하여 그 활성층 위에 drop형식으로 passivation 하였다. 그 결과, drain current (I_DS)가 약 10배 정도 증가하고, linear region(V_D=0.5V)에서 mobility와 subthreshold slope(SS)이 각각 6.7에서 12.2, 0.3에서 0.2로 향상되는 것이 보였다. 이것은 gate bias가 인가되었을 때 freedericksz 전이를 통한 액정의 배향과 이때 형성된 dipole 형성에 의한 것으로 보이며, 이러한 LC의 배향은 편광현미경을 통하여 표면과 수직으로 배향한다는 사실을 확인 할 수 있었고 이 LC-passivation된 a-IGZO TFT의 전기적 특성의 향상에 대한 mechanism을 제시하였다. 그리고 배향한 LC가 가지는 dipole에 의해 bias stress 상황에서 독특한 electron trapping과 recovery의 증폭효과가 나타났다. V_G=+20V의 positive gate bias stress를 1000s동안 가했을 때, passivation되지 않은 a-IGZO TFT의 경우 +4V의 threshold voltage shift(${\Delta}V$_TH)가 발생되었고, 바로 -20V의 negative gate bias를 30s간 가해주었을 때 -2.5V의 ${\Delta}V$_TH가 발생하였다. 반면 LC-passivation된 a-IGZO TFT의 경우 각각 +5V와 -4V의 ${\Delta}V$_TH로 더 큰 변화를 가져왔다. 이러한 LC에 의한 electron trapping/recovery 증폭효과에 대한 model을 제시하였다.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.315-319
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• 2015

Purpose: The purpose of this study was to investigate the effect of leg-crossing positions on muscle activities of rectus femoris, tensor fascia latae, and hamstring in healthy 20's adults. Methods: Twenty healthy subjects were asked to perform three leg-crossing positions, leg crossing (LC), tailor crossing (TC), and ankle crossing (AC). Surface electromyography (EMG) was used to evaluate the activities of rectus femoris, tensor fascia latae, and hamstring during upright sit posture (UP) and three leg-crossing positions and UP was compared to three leg-crossing positions. Repeated one way ANOVA was used for data analysis. The alpha level was set at 0.05. Results: The results showed significant difference in the muscle activities of rectus femoris, tensor fascia latae, and hamstring among leg-crossing positions. The muscle activity of the rectus femoris was significantly lower in LC and TC positions than UP. The muscle activity of tensor fascia latae was significantly higher in LC position than UP and other leg-crossing positions. The muscle activity of hamstring was significantly higher in LC and TC positions and significantly lower in AC position than in UP. Conclusion: Our study suggests that the activity of hip muscles was affected by pelvic and knee alignment in various leg-crossing positions.

• Journal of the Korean Ceramic Society
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• v.28 no.9
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• pp.675-682
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• 1991

Among many problems that need to be solved in the process of preparing multilayer chip LC filters, we studied the control of shrinkage in order to prevent the crack, warpage, and/or delamination which occurs at the interface between the inductance (L part) and the capacitance (C part). Shrinkage was controlled by compositions, powder size, calcining temperature and amount of organic binder. Capacitance sheet was prepared by mixing 65 wt% binder with the composition of 96 wt% TiO2 having an average particle size of 0.5 $\mu\textrm{m}$, 3 wt% CuO. After small amount of MnO2 and SiO2 added, it was calcined at 750$^{\circ}C$ for 2 hr. Inductance sheet was prepared by mixing 60 wt% binder with the composition of 49.5% mol% Fe2O3, 20.5 mol% ZnO, 20 mol% NiO and 10 mol% CuO which was calcined at 775$^{\circ}C$ for 2 hr. These sheets was laminated at 250 kg/$\textrm{cm}^2$, and cofired at 900$^{\circ}C$ for 2 hr to give rise to a multilayer chip LC filter without any warpage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.510-514
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• 2003

We have studied the alignment of liquid crystals (LCs) on homeotropic polymeric surface that is scanned using an atomic force microscope (AFM) tip by optical polarizing microscopy and computer simulation. The scanned areas on one substrate are 5 $\mu\textrm{m}$ ${\times}$ 5 $\mu\textrm{m}$, 10 $\mu\textrm{m}$ ${\times}$ 10 $\mu\textrm{m}$, and 20 $\mu\textrm{m}$ ${\times}$ 20 $\mu\textrm{m}$ and this substrate is assembled to another substrate coated. with homeotropic polymer. The fabricated micro-LC cell using two substrates does not show any hysteresis and disclination lines inside the nano-rubbing areas, while changing voltage up and down. This indicates that the pretilt angle exists in the areas, thereby forming a hybrid LC configuration. From the experimental and computer simulation results, we can understand that the AFM rubbing clearly changes surface status of homeotropic alignment layer and causes the pretilt angle to an initial scanning direction.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.475-479
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• 1992

The non-steroidal ecdysone agonist RH 5849 showed almost similar LC.o values( 18.1-26.5 ppm) at all stages of larval development of the tobacco cutworm, Spodoptera litura, when treated by a leaf-disk dipping method. The feeding-inhibition rate for the 4th instar larvae was dose-dependent, and simultaneously the weight gain of 3rd instar larvae ceased within 48 hour after feeding of the cabbage leafdisk dipped into RH 5849 4.2 ppm solution. The systemic larvicidal effect of RH 5849 was compared at cabbage and tobacco whole plant test. The $LC_{50}$ values below 20 ppm(mg/kg soil) was lasted for 15 days in cabbage, 30 days in tobacco respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.659-666
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• 2021

This study aimed to investigate the effect of changes in pressure levels and gaze directions on deep neck flexor muscle thickness. Twenty-seven subjects participated in this study. Ultrasound imaging of the longus colli (LC) and sternocleidomastoid (SCM) were measured in four gaze directions (0°, 20°, 40°, 60°) and five pressure levels (20 mmHg, 22 mmHg, 24 mmHg, 26 mmHg, 28 mmHg) during cranial-cervical flexor (CCF) exercises. Repeated ANOVA was performed for analysis of muscle thickness difference according to gaze direction and pressure levels in LC and SCM. Results: LC showed a significant difference between 0° and 20°, 0° and 40°, and 0° and 60° at pressures of 20 mmHg and 22 mmHg (p<.05). SCM displayed a significant difference between 0° and 20°, 20° and 40°, and 40° and 60° at 28 mmHg (p<.05). In this study, it was found that setting the gaze direction to 20° for the CCF exercise can increase the activation of LC and lower the activity of SCM to obtain the effect of exercise. Based on the results of this study, it is hoped that the beneficial effects of the CCF exercise can be increased by setting an optimal gaze direction in a clinical environment.

• Journal of Information Display
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• v.2 no.3
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• pp.32-38
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• 2001

The most important parameter for TV application of LCD is a fast switching time for the display of moving image. To achieve faster switching time, the novel LC single materials with large dielectric anisotropies ($16{\sim}20$), high clearing temperatures ($195.5{\sim}237.4^{\circ}C$), broad nematic ranges (up to 169.9 $^{\circ}C$) and high birefringence ($0.254{\sim}0.2200$) were developed. KUR-series LC mixtures blended these single materials having significantly higher clearing temperatures and dielectric anisotropy values compared with conventional LC mixture. Especially, their clearing temperatures are $10{\sim}30^{\circ}C$ higher than their host mixture. These LC mixtures showing about lOms of high-speed switching time in Tv/Monitor of TFT LCD, is short enough to be addressed in a single time frame of 60Hz (16.7 ms). The threshold voltage $V_{th}$ was low enough to operate at a driving voltage of 5 V. The VHR values were found to be high enough for TFT-LCD in wide temperature range. Our novel LC mixtures are suitable materials for the inclusion in to LC mixtures for TV application of TN-LCD

• Kyungpook Mathematical Journal
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• v.20 no.2
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• pp.211-215
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• 1980

• Water for future
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• v.25 no.2
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• pp.61-66
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• 1992

This study was to determine the static acute toxicity on Daphnia magna for the Electric cable Factory Wastewater. Activated sludge process was used to treat the wastewater with three different F/M ratios, 0.36, 0.2, 0.1 mg COD/day.mg MLSS. The results of laboratory bioassay with Daphnia magna were as follows. 1)24hr, 48hr-LC$ of the influent were 17.33% and 11.73%. 2)24hr-LC $ of effluents treated with F/M ratio 0.36,0.26 and 0.1mg COD/day.mg MLSS were 26.69% 32.70% and 38.36% respectively, 48-LC$ of these effluents were 14.48% 27.88% and 31.58% respectively. 3)According to various F/M ratios, the ratios of dffluent 48hr-LC$ to filtrated 48hr-LC$ were 1.58, 1.83 and 1.47respectively 4)Activated sludge process effluents treated with activated carbon had little toxicity on Daphnia magna.