• YAKHAK HOEJI
• /
• v.46 no.5
• /
• pp.337-342
• /
• 2002

Propofol(2,6-diisopropyl phenol) is a phenol derivative that is chemically distinct from other intravenous sedative hypnotics. It has been extensively used as a short term anesthetic agent, because of the rapid onset and short duration of action. Propofol microemulsion system was prepared with different concentrations of ethyl oleate, $Solutol^{(R)}$ HS 15 and $Kollidon^{(R)}$ 17 PF. Propofol microemulsions were studied by transmittance, viscosity, particle size, in vitro release and pharmacokinetics. The range of transmittance of A group with 4% ethyl oleate and that of B group with 5% ethyl oleate were 92.6~95.1 and 91.3~94.2%, respectively. Transmittance 1~2% decreased as concentration of $Kollidon^{(R)}$ 17 PF was increased and increased 0.8~3.3% when 10 times diluted with normal saline. The viscosity of A and B group were in the range of 3.9~4.1 mPaㆍsec and 4.4~5.3 mPaㆍsec, respectively. The particle sizes of A and B group increased as amount of $Kollidon^{(R)}$ 17 PF. Also, release of propofol was slowly increased as the amount of $Kollidon^{(R)}$ 17 PF was increased. Propofol plasma concentration by i.v injection showed 2-compartment model. Pharmacokinetics of A-5 was similar to that of commercial emuision(POFOL).

• Electrical & Electronic Materials
• /
• v.8 no.6
• /
• pp.811-815
• /
• 1995

회토류계 영구자석은 종래의 Ferrite계나 Alnico계와 비교해서 대단히 강하여, 전기전자부품의 소형화에 크게 기여하고 있다. 최근에는, 전자기기산업 이외의 분야에 있어서도 그의 응용이 확대되어가고 있는 추세로 자성재료의 생산액은 매년 증가하고 있다. 회토류계 영구자석재료의 연구는 1960년대에 시작되어 Sm $Co_{5}$, Sm$_{2}$ $Co_{17}$ 화합물의 등장을 거쳐 현재는 1982년데 Sagawa 및 Croat가 독자적으로 발견한 Nd$_{2}$ Fe$_{14}$B 자석이 주류로 되고 있다. 그렇지만 이 화합물에는 다른 영구자석에 비하여 큐리온도가 낮은 결점이 있어서, 아직도 새로운 화합물의 탐색이 계속되고 있다. 그 중에서도, 1990년대에 Coey에 의해서 최초로 학회지에 보고되어진 Sm$_{2}$Fe$_{17}$N$_{x}$는, Nd$_{2}$Fe$_{14}$B와 같은 정도의 이론 최대에너지급, Sm $Co_{5}$에 대등한 거대한 이방성자장, 750K에 달하는 큐리온도등의 우수한 성질을 갖고 있어 Nd$_{2}$Fe$_{14}$B를 극복하는 자성재료로서 큰 기대가 되어진다. 되어진다.진다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.2C
• /
• pp.175-180
• /
• 2009

When we apply the LDPC code for high density optical storage channel, it is necessary to make an algorithm that the modulation code decoder must feed the LDPC decoder soft-valued information because LDPC decoder exploits soft values using the soft input. Therefore, we propose the soft-input soft-output run-length limited 17PP decoding algorithm and compare performance of LDPC codes. Consequently, we found that the proposed soft-input soft-output decoding algorithm using 17PP is 0.8dB better than the soft-input soft-output decoding algorithm using (1, 7) RLL.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.5A
• /
• pp.519-527
• /
• 2010

In this paper, we design and implement a broadband LNA(Low Noise Amplifier), a mixer, and oscillators in RF module part for radar detector. For resolving the limitation of the conventional product that the sensitivity is low due to the poor gain flatness, we propose the architecture of RF module part. The proposed RF module part is composed with a broadband 2-stage LNA, a mixer, and three oscillators, and improves the maximum gain and gain flatness for detecting various frequencies. The overall performances of RF module part are above 38 dB conversion gain in whole band and 1 dB gain flatness. These results show that the maximum gain which is the problem of the conventional product is improved 6 dB from 35 dB to 41 dB, and gain flatness is also improved 17 dB from 22 dB to 5 dB.

• Journal of IKEEE
• /
• v.28 no.1
• /
• pp.33-37
• /
• 2024

In this paper, we report the design and the measurement of a X-band low noise amplifier (LNA) monolithic microwave integrated circuit (MMIC) using a 0.25 ㎛ gate length microstrip GaN-on-SiC high electron mobility transistor (HEMT) technology. The developed X-band GaN-based LNA MMIC achieves small signal gain of 22.75 dB ~ 25.14 dB and noise figure of 1.84 dB ~ 1.94 dB in the desired band of 9 GHz to 10 GHz. Input and output return loss values are -11.36 dB ~ -24.49 dB and -11.11 dB ~ -17.68 dB, respectively. The LNA MMIC can withstand 40 dBm (10 W) input power without performance degradation. The chip dimensions are 3.67 mm × 1.15 mm. The developed GaN-based LNA MMIC is applicable to various X-band applications.

• Preventive Nutrition and Food Science
• /
• v.17 no.4
• /
• pp.306-309
• /
• 2012

This study was performed to investigate the potential use of Saussurea lappa C.B. Clarke as a source of antioxidant agents. Various solvent fractionates from S. lappa C.B. Clarke roots were investigated for their anti-oxidative effectiveness. The contents of total phenolics and flavonoids were determined by the Folin-Ciocalteu's colorimetric and the aluminum nitrate method, respectively. Total phenolic and flavonoid contents of n-butanol soluble fractionates from S. lappa C.B. Clarke, 44.43 ${\mu}g$ gallic acid equilibrium (GAE)/g extract and 92.15 ${\mu}g$ quercetin equilibrium (QE)/g extract, respectively, were higher than those of other solvent fractionates. The n-butanol soluble fractionates of S. lappa C.B. Clarke (1,000 ppm) showed the strongest inhibitory potential on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and reducing power at 92.98% and 0.38, respectively. Thus, our data shows that the S. lappa C.B. Clarke plant may help prevent antioxidative stress.

• Journal of Korean society of Dental Hygiene
• /
• v.14 no.1
• /
• pp.85-93
• /
• 2014

Objectives : The purpose of the study is to investigate and compare the knowledge of hepatitis B in nursing and dental hygiene students in Busan. Methods : A self-reported questionnaire was filled out by 361 students in nursing and dental hygiene departments in Busan from August 25 to September 4, 2013. Data were analyzed by SPSS version 13.0 for descriptive statistical analysis, ${\chi}^2$-test, and t-test and set at p<0.05. Results : Knowledge in hepatitis B consisted of 25 questions including severity of hepatitis B, general knowledge, infection routes, and symptoms and treatment. There was no significant difference between nursing and dental hygiene students in knowledge; nursing students showed an average of $18.21{\pm}2.809$ and dental hygiene showed $17.71{\pm}3.23$. The average score was $17.96{\pm}3.03$ out of 25 questions. Conclusions : There is no significant difference between nursing and dental hygiene students in knowledge of hepatitis B. It is necessary to emphasize the education of hepatitis B periodically in addition to regular curricula.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.8
• /
• pp.764-768
• /
• 2002

In this paper, a double balanced gilbert cell MMIC mixer was realized in Tachyonics SiGe HBT technology. The fabricated mixer has 17 dB conversion gain, 9.8 dB noise figure, -4.2 dBm output 1 dB compression point, -27 dBc RF to IF isolation, and the good input, output matching characteristics. It draws 10 mA from a 3 V supply. The simulation and the measured results are closer to each other, which confirms accuracy of the model library and reliability of the process.

• Korean Journal of Optics and Photonics
• /
• v.17 no.5
• /
• pp.475-479
• /
• 2006

An integrated photonic K-band microwave bandpass filter has been proposed and demonstrated by incorporating a polymeric ring resonator. Its transfer characteristics were adjusted by shilling the resonance wavelength of the ring resonator via the thermooptic effect. The achieved performance of the filter includes the center frequency of 20 GHz, the attenuation of ${\sim}15dB$, the bandwidth of 2 GHz, and the corresponding quality factor of 10. The microwave output power within the passband of the device was adjusted at the rate of about 6.7 dB/mW in the range of 27 dB. This kind of device with electrically controllable transfer characteristics can be applied to implement microwave switches and other devices.

• Korean Journal of Food Science and Technology
• /
• v.47 no.5
• /
• pp.579-585
• /
• 2015

Following supplementation with organic acids (acetic, citric, and lactic acids), the pH of the alcohol mash changed from 4.2 control to 3.73-3.97 supplemented, the acidity from 5.06 to 8.13-9.98, and the alcohol content from 17.8 to 17.0-17.8%. Protease activity decreased owing to the pH change, and the total nitrogen content decreased by 13.1-36.9% following organic acid supplementation. Organic acid supplementation did not affect the distillation efficiency; however, thiobarbituric acid values in the crude distillate (40%) decreased 2.2-3.6 fold following supplementation with citric acid and lactic acid. The total isobutanol (B), isoamyl alcohol (A), and 1-propanol (P) contents in each soju (25%) supplemented with organic acid were 1,041.47, 979.50, and 961.48 ppm, respectively, which were higher than those in the control soju (935.27 ppm). The A/P, A/B, and B/P ratios of soju were altered and the acetaldehyde content decreased following supplementation with the organic acid.