• Tribology and Lubricants
• /
• 제15권3호
• /
• pp.278-286
• /
• 1999

To predict the behavior of the intravascular micro active endoscope in the real human vascular system, a human mock circulation system was developed. The intravascular micro active endoscope which consists of micro active bending catheter and micro drug infusion catheter was driven in the velocity, Re number and temperature controlled flow. The three SMA (Shape Memory Alloy) zigzag type spring in the micro active bending catheter was heated by the electric current generated by PWM controller, and the shape memory effect made the actuator bend to any direction. The micro drug infusion catheter was driven through the inner hole of the micro active bending catheter. A mock circulation system is shaped from Ascending Arota to Femoral artery according to a human data (the data contains many vascular sizes and hydrographs of many control points). We developed a vascular model with glass and silicone tubes, and set the flow system with circulation parts, flow settling parts, and lots of valves. The heater and heat-controller was added to the How system to centre! the temperature of the How at 36.5$^{\circ}C$. The result showed that the developed intravascular micro active endoscope could be induced to any point in the vascular model.

• Nuclear Engineering and Technology
• /
• 제54권10호
• /
• pp.3919-3927
• /
• 2022

This study presents an optimal design of the coolant system of a non-refueling full-life small reactor by analyzing the space-integrated geometrical and electromagnetic variables of an extra vessel electromagnetic pump (EVEMP) for the circulation of a lead-bismuth eutectic (LBE) coolant. The EVEMP is an ideal alternative to the thermal-hydraulic system of non-refueling full-life micro reactors as it possesses no internal structures, such as impellors or sealing structures, for the transportation of LBE. Typically, the LBE passes through the annular flow channel of a reactor, is cooled by the heat exchanger, and then circulates back to the EVEMP flow channel. This thermal-hydraulic flow method is similar to natural circulation, which enhances thermal efficiency, while providing a golden time for cooling cores in the event of an emergency. When the forced circulation technology of the EVEMP was applied, the non-refueling full-life micro reactor achieve an output power of 60 MWt, which is higher than that achievable via the natural circulation method (30 MWt). Accordingly, an optimized EVEMP for Micro URANUS with a flow rate of 4196 kg/s and developed pressure of 73 kPa under a working temperature of 250 ℃ was designed.

• 대한의용생체공학회:의공학회지
• /
• 제43권4호
• /
• pp.214-218
• /
• 2022

The purpose of this study was to investigate the role of the PMF in the treatment of acidosis and inflammation by monitoring the pH change for the continuity of PMF effect on the blood in the micro-circulation system that mimics the capillaries in the human body. Micro-tubes and micro-channels similar in diameter to those of arteries and arterioles were fabricated using PDMS and connected to a micro-pump for blood circulation. The continuity of PMF effect was verified in a micro-circulation system in-vitro. The pH changes for the circulating blood and for persistence time of PMF stimulus effect were confirmed using the optimized PMF conditions based on the previous studies. Also pH changes were observed by continuously stimulating PMF for a set period of time. The result was observed that the pH of the blood acidified using tBHP continued to rise from immediately after stimulation of PMF to 70 minutes of stimulation, reaching a normal pH range, and then decreasing. Our study showed that PMF has a positive effect on the control of blood pH homeostasis, so it is suggested the possibility of being used as a noninvasive treatment for acidosis treatment and anti- inflammatory treatment.

• 대한조선학회논문집
• /
• 제48권1호
• /
• pp.93-97
• /
• 2011

When freezing is present on ballast water, it can impose additional loads on the hull and effect on stabilization of ship. The anti-icing techniques of ballast water, therefore, are key criteria for ship safety. The existing anti-icing techniques of ballast tank are hull heating, water circulation and air bubble system etc. In this research, anti-icing performance tests for the ballast water using micro-bubble system and sea water circulation system have been carried out at two temperature conditions($-10^{\circ}C$ and $-25^{\circ}C$). Ambient temperature, sea water temperature and temperature of the inner parts of the ballast tank are measured and also ballast water conditions are checked during the model test. The applied anti-icing techniques of ballast water, such as micro-bubble system and sea water circulation system show good performance in the low temperature conditions.

• 순환기질환의공학회:학술대회논문집
• /
• 순환기질환의공학회 2005년도 제5회 학술대회 초록집
• /
• pp.33-34
• /
• 2005

• 순환기질환의공학회:학술대회논문집
• /
• 순환기질환의공학회 2005년도 제5회 학술대회 초록집
• /
• pp.39-40
• /
• 2005

• 순환기질환의공학회:학술대회논문집
• /
• 순환기질환의공학회 2001년도 제1회 학술대회 초록집
• /
• pp.31-32
• /
• 2001

• 순환기질환의공학회:학술대회논문집
• /
• 순환기질환의공학회 2001년도 제1회 학술대회 초록집
• /
• pp.22-23
• /
• 2001

• 순환기질환의공학회:학술대회논문집
• /
• 순환기질환의공학회 2004년도 제4회 학술대회 초록집
• /
• pp.44-45
• /
• 2004

• International Journal of Vascular Biomedical Engineering
• /
• 제1권2호
• /
• pp.30-35
• /
• 2003

Flow characteristics of blood flow in a micro channel were investigated experimentally using a micro-PIV (Particle Image Velocimetry) velocity field measurement technique. The main objective of this study was to understand the real blood flow in micron-sized blood vessels. The Reynolds number based on the hydraulic diameter of micro-channel for deionized (DI) water was about Re=0.34. For each experimental condition, 100 instantaneous velocity fields were captured and ensemble-averaged to get the spatial distributions of mean velocity. In addition, the motion of RBC (Red Blood Cell) was visualized with a high-speed CCD camera. The captured flow images of nano-scale fluorescent tracer particles in DI water were clear and gave good velocity tracking-ability. However, there were substantial velocity variations in the central region of real blood flow in a micro-channel due to the presence of red blood cells.