• Fisheries and Aquatic Sciences
• /
• 제12권3호
• /
• pp.194-202
• /
• 2009

Sulfated fucans are known to have both anti-thrombotic and anti-coagulant activities. In this study, the variation in platelet aggregation and anti-coagulant activities was investigated in vitro with regard to administered dose, molecular weight distribution, sulfate content, and sugar composition in two algal fucoidans from Eisenia bicyclis and Undaria pinnatifida sporophylls (Mekabu). The anti-coagulant activity largely correlated with sulfate content and with molecular weight distribution in a dose-dependent manner. However, both fucoidans demonstrated inhibitory responses to ADP-induced platelet aggregation in dose- and structure-dependent manners that contrasted with the anti-coagulant activity. Neither molecular weight distribution nor sulfate content greatly affected platelet-aggregation inhibition (PA-inhibition) by the fucoidan fractions, whereas anti-coagulant activity was sensitive to these structural factors. Interestingly, an E. bicyclis fucoidan fraction exhibited almost complete PA-inhibition at a treatment dose of 500 mg/mL while retaining weak anti-coagulant activity. In conclusion, these observations suggest that fucoidan may be a useful anti-thrombotic or anti-platelet agent in various arterial thrombotic disorders, including post-vascular intervention with controlled bleeding complications, due to its anti-coagulant modulating activity.

• 한국수산과학회지
• /
• 제47권3호
• /
• pp.292-301
• /
• 2014

The objective of this study was to design and develop a broadband ultrasonic transducer that has both wide bandwidth and high sensitivity to measure broadband echoes related to identifying fish species. A broadband ultrasonic transducer providing a nearly flat transmitting response band of 40.2-75.5 kHz with a -12 dB bandwidth of 35.3 kHz was achieved by integrating 12 tonpilz transducer elements operating at different resonance frequencies. The average transmitting voltage response, receiving sensitivity, and figure of merit values in this frequency band were 168.4 dB (re $1{\mu}Pa/V$ at 1 m), -196.8 dB (re $1V/{\mu}Pa$), and -28.4 dB, respectively. The results suggest that bandwidth and sensitivity can be widened and improved by adjusting the array pattern and the structure of tonpilz transducer elements.

• Preventive Nutrition and Food Science
• /
• 제12권2호
• /
• pp.122-125
• /
• 2007

Gelidium corneum films were prepared using cinnamaldehyde as a cross-linking agent and their physical properties were determined. Tensile strength (TS) value of the film containing 0.01% cinnamaldehyde was higher than the control by 8.31 MPa. However, increasing cinnamaldehyde from 0.01% to 0.1% significantly decreased TS from 9.54 MPa to 0.03 MPa, and no film was formed at 1% cinnamaldehyde. On the contrary, when cinnamaldehyde content was increased from 0.01% to 0.1%, % elongation was increased from 1.44% to 2.75%. Water vapor permeability (WVP) of the film containing 0% and 0.01% cinnamaldehyde were 1.64 ng m/m$^2$sPa and 1.42 ng m/m$^2$sPa, respectively. There was no significant difference in Hunter values among treatments. Scanning electron microscopy results revealed that both cinnamaldehyde and control films had similar surfaces. These results suggest that 1.5% Gelidium corneum treated with 0.01% cinnamaldehyde should be the most suitable condition for film formation.

• 한국정밀공학회지
• /
• 제31권12호
• /
• pp.1107-1113
• /
• 2014

In this article, the megasonic cleaning system for cleaning micro/nano particles from flat panel display (FPD) surfaces was developed. A piezoelectric actuator and a waveguide were designed by finite element method (FEM) analysis. The calculated peak frequency value of the quartz waveguide was 1002 kHz, which agreed well with the measured value of 1003 kHz. The average acoustic pressure of the megasonic cleaning system was 43.1 kPa, which is three times greater than that of the conventional type of 13.9 kPa. Particle removal efficiency (PRE) tests were performed, and the cleaning efficiency of the developed system was proven to be 99%. The power consumption of the developed system was 64% lower than that of the commercial system. These results show that the developed megasonic cleaning system can be an effective solution in particle removing from FPD substrate with higher energy efficiency and lower chemical and ultra pure water (UPW) consumption.

• 한국기계가공학회지
• /
• 제18권12호
• /
• pp.1-6
• /
• 2019

Aluminum liners used in cylinders are hazardous for human health. In this study, we use a plastic PA liner inside cylinders to solve this problem. Plastic PA liners are widely used in the manufacturing industry in the production of food and beverage containers. We covered the aluminum boss with a plastic liner material and wound the composite fibers over the liner material. To reinforce the dome area, we used low strength / high elongation plastic liner. To predict the performance of the developed product, we conducted structural analyses utilizing the 3D laminated solid element. We verified the soundness of the product by testing the prototype.

• Journal of Chest Surgery
• /
• 제24권10호
• /
• pp.960-966
• /
• 1991

From February 1984 through July 1991, 104 infants less than 1 year of age with congenital heart defects underwent open heart repair with conventional cardiopulmonary bypass which occupied 10.7% of all patients with congenital heart defects operated on during same period. There were 66 boys and 38 girls 7 days to 12 months [mean age, 8.2 months]. Four patients were neonates, 8 were 1 to 3 months, 23 were 4 to 6 months, and 69 were 7 to 12 months of age. Mean body weight at repair was 6.9kg and mean BSA, 0.36m2 Indications for operation were intractable congestive heart failure and severe pulmonary hypertension in patients with VSD and severe cyanosis and anoxic spells in patients with TOF. Conditions corrected were VSD[79], TOF[8], AVSD[4], PS[2], PA+IVS[2], TAPVC [2], MR[2], DOLV[l], Truncus arteriosus[1], D-TGA[1], and PA-VSD[1]. Twenty-three of 79 patients with VSD had associated cardiovascular anomalies which included PDA in 16 patients, PS in 9 patients, ASD in 5 patients, LSVC in 2 patients, MR in 1 patient, dextrocardia in 1 patient, and single coronary artery in 1 patient. The hospital mortality rate was 24.0% which was much higher than that of 6% in patients over 1 year of age. The greatest mortality occurred in babies of low weight under 6 months of age, There was no late death. Surviving infants showed marked symptomatic improvement and change in growth patterns. These surgical results were to be overcome with proper pre- and post-operative management and improvement of surgical technique

• 대한의용생체공학회:의공학회지
• /
• 제41권1호
• /
• pp.1-7
• /
• 2020

Polyvinyl alcohol (PVA)/gelatin hydrogels were prepared by repeating freezing/thawing three times to evaluate the influence of PVA concentration on the strength and the cell growth behavior of the PVA/gelatin hydrogels. The swelling rate of the PVA/gelatin hydrogels decreased with raising the PVA content from 6 wt% to 12 wt% due to the formation of 3-D network inside the hydrogel. No appreciable degradation of the hydrogels was detected. As the PVA content increased from 6 wt% to 12 wt%, the strength of the PVA/gelatin hydrogels increased drastically from 6.4±0.9 kPa to 46.6±9.0 kPa. The PVA/gelatin hydrogels did not show any evidence of causing cell lysis or toxicity, implying that the hydrogels are clinically safe and effective. Although the strength increased with increasing the PVA content, the PVA/gelatin hydrogels containing 8 wt% exhibited the fastest cell growth, which is highly suitable for wound dressing requiring fast healing regeneration.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제14권4호
• /
• pp.443-450
• /
• 2014

This paper presents a 20-Gb/s optical receiver circuit fabricated with standard 65-nm CMOS technology. Our receiver circuits are designed with consideration for parasitic inductance and capacitance due to bonding wires connecting the photodetector and the circuit realized separately. Such parasitic inductance and capacitance usually disturb the high-speed performance but, with careful circuit design, we achieve optimized wide and flat response. The receiver circuit is composed of a transimpedance amplifier (TIA) with a DC-balancing buffer, a post amplifier (PA), and an output buffer. The TIA is designed in the shunt-feedback configuration with inductive peaking. The PA is composed of a 6-stage differential amplifier having interleaved active feedback. The receiver circuit is mounted on a FR4 PCB and wire-bonded to an equivalent circuit that emulates a photodetector. The measured transimpedance gain and 3-dB bandwidth of our optical receiver circuit is 84 $dB{\Omega}$ and 12 GHz, respectively. 20-Gb/s $2^{31}-1$ electrical pseudo-random bit sequence data are successfully received with the bit-error rate less than $10^{-12}$. The receiver circuit has chip area of $0.5mm{\times}0.44mm$ and it consumes excluding the output buffer 84 mW with 1.2-V supply voltage.

• 한국정보통신학회논문지
• /
• 제12권8호
• /
• pp.1415-1419
• /
• 2008

본 논문에서는 인터넷 기반 전송기술인 TCP/IP 네트워크의 한 분야인 AoIP(Audio over Internet Protocol)를 기반으로 한 음향전송시스템을 구현하기 위하여 최근 들어 연구하고 있는 다양한 음향전송 시스템들을 탐구하여 가장 효율적으로 구현이 가능한 전송방법을 채택하여 AoIP기반 음향전송시스템의 설계와 구현을 하였다. 구현된 시스템은 소규모의 구내 방송시스템을 비롯하여 대규모의 분산 네트워크가 필요한 다양한 프로페셔널 음향 시스템에 적용 할 수 있으며, 향후 다양한 분야에 응용하여 자동으로 음향신호를 전송하는 시스템으로의 확장 가능성을 제시하였다.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2006년도 하계학술발표대회 논문집
• /
• pp.560-565
• /
• 2006

스프링클러설비는 능동적 소화시스템 중 가장 효과적이며 신뢰성이 높은 시스템이다. 또한 스프링클러설비를 설치함으로써 방화구획을 완화할 수 있으며 특별피난계단의 부속실 및 비상용승강기의 승강장의 급기가압시스템에서 차압을 12.5Pa(스프링클러설비가 설치되지 않은 경우 25Pa)으로 할 수 있으므로 경제적인면도 고려되어질 수 있다. 이에 관한 보다 상세한 내용을 별도의 논문으로 다룰 것이다.