• The KSFM Journal of Fluid Machinery
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• v.9 no.5 s.38
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• pp.28-35
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• 2006

Orbiter mechanism has been applied to vacuum pump design for small oxygen generator where low vacuum of about 200 mmHg is required. Performance of the designed vacuum pump has been numerically investigated: calculated volumetric and adiabatic efficiencies were 69.7% and 83.9%, respectively for leakage clearance of $10{\mu}m$. Total efficiency of the orbiter vacuum pump was 77.5%. At the shaft speed of 1700 rpm suction displacement volume of 6.3cc provided discharge flow at the rate of 2.3 liter/min with power consumption of 10.1Watt. Torque variation of the orbiter pump was only about 20% of that of diaphragm pump.

• International Journal of Fluid Machinery and Systems
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• v.10 no.2
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• pp.138-145
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• 2017

The problem of non-uniform inflow exists in many practical engineering applications, such as the elbow suction pipe of waterjet pump and, the channel head of steam generator which is directly connect with reactor coolant pump. Generally, pumps are identical designs and are selected based on performance under uniform inflow with the straight pipe, but actually non-uniform suction flow is induced by upstream equipment. In this paper, CFD approach was employed to analyze unsteady hydrodynamic characteristics of reactor coolant pumps with different inflows. The Reynolds-averaged Naiver-Stokes equations with the $k-{\varepsilon}$ turbulence model were solved by the computational fluid dynamics software CFX to conduct the steady and unsteady numerical simulation. The numerical results of the straight pipe and channel head were validated with experimental data for the heads at different flow coefficients. In the nominal flow rate, the head of the pump with the channel head decreases by 1.19% when compared to the straight pipe. The complicated structure of channel head induces the inlet flow non-uniform. The non-uniformity of the inflow induces the difference of vorticity distribution at the outlet of the pump. The variation law of blade to blade velocity at different flow rate and the difference of blade to blade velocity with different inflow are researched. The effects of non-uniform inflow on radial forces are absolutely different from the uniform inflow. For the radial forces at the frequency $f_R$, the corresponding amplitude of channel head are higher than the straight pipe at $1.0{\Phi}_d$ and $1.2{\Phi}_d$ flow rates, and the corresponding amplitude of channel head are lower than the straight pipe at $0.8{\Phi}_d$ flow rates.

• Archives of Plastic Surgery
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• v.44 no.1
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• pp.42-47
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• 2017

Background Skin erosion is a dire complication of implantable cardiac pacemakers and defibrillators. Classical treatments involve removal of the entire generator and lead systems, however, these may result in fatal complications. In this study, we present our experience with a simplified salvage technique for exposed implantable cardiac electronic devices (ICEDs) without removing the implanted device, in an attempt to reduce the risks and complication rates associated with this condition. Methods The records of 10 patients who experienced direct ICED exposure between January 2012 and December 2015 were retrospectively reviewed. The following surgical procedure was performed in all patients: removal of skin erosion and capsule, creation of a new pocket at least 1.0-1.5 cm inferior to its original position, migration of the ICED to the new pocket, and insertion of closed-suction drainage. Patients with gross local sepsis or septicemia were excluded from this study. Results Seven patients had cardiac pacemakers and the other 3 had implantable cardiac defibrillators. The time from primary ICED placement to exposure ranged from 0.3 to 151 months (mean, 29 months. Postoperative follow-up in this series ranged from 8 to 31 months (mean follow-up, 22 months). Among the 10 patients, none presented with any signs of overt infection or cutaneous lesions, except 1 patient with hematoma on postoperative day 5. The hematoma was successfully treated by surgical removal and repositioning of the closed-suction drainage. Conclusions Based on our experience, salvage of exposed ICEDs is possible without removing the device in selected patients.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.688-693
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• 2014

This study is to increase the utilization of the ozonated water generator to make it easier to take advantage of the ozone water in the world today, there will be to develop a system that operates in one motion. Furthermore, olive oil and ozone is reacted with the wish to apply to the manufacturing technology. In the case of many existing products ozone generator driven mostly non-ozone system. In the case of ozone, but handwriting is implied general way pressure ozone gas leakage risks of suction force to the pump, it is the case of the challenge by using the injector, and limit the generation of ozone and ozone inhalation according to whether the water inlet leakage of existing products risk due to minimized. Despite the disadvantages of the injector system was found the effectiveness of the ozonated water production unit injector system used in this study to maintain the microbiological disinfection performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.941-945
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• 2006

In the development of electricity generating wind turbines for wind farm application, only two types have survived as the methods of power regulation; stall regulation and fun span pitch control. The sound measurement procedures of IEC 61400-11 are applied to field test and evaluation of noise emission from each of 1.5 MW and 660 kW wind turbine generators (WTG) utilizing the stall regulation and the pitch control for the power regulation, respectively. Apparent sound power level, wind speed dependence and third-octave band levels are evaluated for both of WTGs. It is found that while 1.5 MW WTG using the stall control is found to emit lower sound power than 660 kW one using the pitch control at low wind speed (below 8 m/s), sound power from the former becomes greater than that of the latter in the higher wind speed. Equivalent continuous sound pressure levels (ECSPL) of the stall control type of WTG vary more widely with wind speed than those of the pitch control type of WTG These characteristics are believed to be strongly dependent on the basic difference of the airflow around the blade between the stall regulation and the pitch control types of WTG. These characteristics according to the methods of power regulation lead to the very different noise emission characteristics of WTG depending on the seasons because the average wind speed in summer is lower than the critical velocity over which the airflow on the suction side of blade in the stall types of WT are separated. These results propose that, in view of environmental noise regulation, the developer of wind farm should give enough considerations to the choice of power regulation of their WTG based on the weather conditions of potential wind farm locations.