• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.5 no.4
• /
• pp.309-322
• /
• 2007

This study deals with the irradiation effects on some selected components which are being used in an Advanced Spent Fuel Conditioning Process (ACP). Irradiation test components have a higher priority from the aspect of their reliability because their degradation or failure is able to critically affect the performance of an ACP equipment. Components that we chose for the irradiation tests were the AC servo motor, potentiometer, thermocouples, accelerometer and CCD camera. ACP facility has a number of AC servo motors to move the joints of a manipulator and to operate process equipment. Potentiometers are used for a measurement of several joint angles in a manipulator. Thermocouples are used for a temperature measurement in an electrolytic reduction reactor, a vol-oxidation reactor and a molten salt transfer line. An accelerometer is installed in a slitting machine to forecast an incipient failure during a slitting process. A small CCD camera is used for an in-situ vision monitoring between ACP campaigns. We made use of a gamma-irradiation facility with cobalt-60 source for an irradiation test on the above components because gamma rays from among various radioactive rays are the most significant for electric, electronic and robotic components. Irradiation tests were carried out for enough long time for total doses to be over expected threshold values. Other components except the CCD camera showed a very high radiation hardening characteristic. Characteristic changes at different total doses were investigated and threshold values to warrant at least their performance without a deterioration were evaluated as a result of the irradiation tests.

• Polymer(Korea)
• /
• v.30 no.4
• /
• pp.279-285
• /
• 2006

Non-viral gene carriers continue to attract a great deal of interest due to advantageous safety profile. Among the non-viral gene carriers, cationic liposomes or synthetic gene carriers are efficient DNA carriers in vitro. but their in vivo applications are greatly hampered because of low biocompatibility. On the other hand, chitosan, a natural cationic polysaccharide, is a candidate non-viral vector for gene delivery because of its low cytotoxicity and high positive charges. In this work, targeted gene carrier was synthesized to target artery wall cells using low molecular water-soluble chitosan (LMWSC). The molecular weight $(M_W)$ and degree of de acetylation (DDA) of LMWSC were measured by relative viscometer and Kina titration. respectively. The structure of LMWSC was analyzed by measuring FTIR, $^1H-NMR,\;and\;^{13}C-NMR$. AWBP-PEG-g-LMWSC was synthesized by conjugation of the artery wall binding peptide (AWBP), a specific targeting peptide, to the end of pegylated LMWSC as a gene carrier to target artery wall cells. The synthesized AWBP-PEG-g-LMWSC were analyzed by measuring FTIR, $^1H-NMR$, zeta -potentiometer, and atomic force microscopy (AFM).

• Journal of the Korean GEO-environmental Society
• /
• v.8 no.5
• /
• pp.39-46
• /
• 2007

In this study, the centrifuge tests were performed to investigate the lateral flow behavior and stability of the ground improved by SCP. The centrifuge tests were fulfilled in the case of the back of abutment filled by EPS (case 1) and soil (case 2), and the potentiometer was installed on the abutment and embankment to measure the vertical and horizontal displacement at the top of abutment. As a result, the vertical displacement measured at the back of abutment was maximum 2.1 m, which was about 12% if compared with the height of embankment. In the case of the back of abutment filled by soil, the vertical and horizontal displacement measured at the top of abutment was 10 cm and 1.1 m, respectively, which exceeded the allowable horizontal displacement. On the other hand, in the case of the back of abutment filled by EPS, the vertical displacement of abutment did nor occur and the horizontal displacement was 1.4 cm. Therefore, the effect of SCP improvement with EPS method adopted to prevent the lateral flow and assure the stability of embankment on the soft ground was far superior.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.6
• /
• pp.20-26
• /
• 2001

In this paper, we design tunnel inner section displacement measurement system which is composed of potentiometer-type displacement sensors, microcontroller-based intelligent sensing head and host computer for the management system and acquisition data. Multiple node communication bus connects the intelligent sensing heads with the host computer. For safe and re1iab1e network operation we use daisy-chain configuration, termination resistor, fail-safe biasing circuit. For tole enhancement of system utilization, we use modbus protocol. The acquisition data are transmitted to host computer and managed by database. Several data request conditions and sorting conditions are provided by management software. The utilization of designed system is confirmed by experiment.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.6
• /
• pp.121-126
• /
• 2001

Currently, potentiometric method has been employed to measure fuel amount for automobile. However, potentiometer could be malfunctioned or damaged due to the additives or dirt in fuel because a variable electric resistor is immersed in fuel. Therefore, a device employing strain sensor is designed and tested to verify the possibility as an alternative of the conventional fuel sender. Existing fuel tank has irregular cross section. Therefore, buoyancy is not increased linearly as fuel amount is increased. We design a floater that can compensate the irregular cross section of fuel tank and make buoyancy to increase linearly with increasing fuel amount. New fuel sender, comprising of strain gages on circular membrane, the above commented floater and the cover to prevent the disturbance due to sudden acceleration and deceleration, is designed and tested to replace current fuel sender. On the other hand, we are developing strain sensor that has strain gage deposited directly on the circular membrane with cantilever beam.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.7
• /
• pp.319-325
• /
• 2005

In order to analyze ground potential rise of grounding system installed in buildings, the hemispherical grounding simulation system has been designed and fabricated as substantial and economical measures. Ground potential rise(GPR) has been measured and analyzed for shapes of grounding electrode using the system in real time. The system is apparatus to have a free reduced scale for conductor size and laying depth of a full scale grounding system and is constructed so that a shape of equipotential surface is nearly identified a free reduced scale with a real scale when a current flows through grounding electrode. The system was composed of a hemispherical water tank, AC Power supply, a movable potentiometer, and test grounding electrodes. The test grounding electrodes were fabricated through reducing grounding electrode installed in real buildings such as rod type, mesh grid type. When a mesh grid type was associated with a rod type, GPR was the lowest value. The proposed results would be applicable to evaluate GPR in the grounding systems. and the analytical data can be used 0 stabilize the electrical installations and prevent the electrical disasters.

• Journal of Biosystems Engineering
• /
• v.15 no.2
• /
• pp.110-122
• /
• 1990

This study was undertaken to develop the feed rate control system for the head feed thresher by making use of the microprocessor and to evaluate the response of the system to a various threshing conditions. The control unit was composed of one-board microcomputer. The speed of the wet-paddy feeding chain was controlled by dc moter with PI controller. It was used the adaptive control method to maintain the constant feed rate regardless of the fed rice varieties. The sliding type potentiometer was used as the feed rate sensor, which was attached on the sheaf-holding apparatus. The mathematical models of the system components were derived and computer simulation was developed for investigating the parameters affecting on control performance and for estimating the response of the system. A one-board microcomputer-based feed rate control system developed in this study was properly functioned and assessed as adequate for the feed rate control system of the head feed thresher. Based on the simulation for the bundle feed, it was anticipated that the lower setting value of the cylinder speed(RL) is to be set higher than the limiting operational speed. In addition, the higher setting value of the cylinder speed(RH) is to be set lower than the limiting cylinder speed for threshing. The computer simulation for the continuous spread feed showed that the lower the setting value of straw layer thickness(LL) was set, the shorter the correction time. However, if too low LL may be established, the feed rate could not reach to its desired rate.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.8 no.3
• /
• pp.129-136
• /
• 2013

In this paper, a motion control system based on 2-axis gimbal system is designed and implemented to drive a high speed and precision. The proposed system consists of the RS-422 interface, 2-axis gimbal platform, servo control unit integrated with a high speed DSP chip-set, servo amplifier unit, potentiometer sensor unit, and resolver sensor unit. The servo control unit using the high speed DSP firmware is designed to get a fast response without an overshoot with step input and a RMS error of low probability with ramp input. The servo amplifier unit using a voltage control is designed to resolve the zero-crossing distortion for precise motion. To verify the performance and stability of the implemented system, experiments are performed through a measurement of the time and frequency domain response in a laboratory environment by using a PXI(PCI eXtentions for Instrumentation).

• Korean Journal of Agricultural Science
• /
• v.37 no.1
• /
• pp.123-130
• /
• 2010

A steering control system based on CAN(Controller Area Network) for autonomous tractor was developed to reduce duty of a central processing computer and to improve performance of steering control in terms of reduced control interval and error. The steering control system consisted of a SCU (Steering Control Unit), an EHPS system, and a potentiometer. The SCU consisted of an MCU (Micro Controller unit), an A/D converter, and a DC-DC converter, and a PID controller was used to control steering angle. The steering control system was communicated with the computer by CAN-bus. Each actuator and implement was connected to a multi-function board interfacing with the computer through a USB cable. Without CAN, control interval of the autonomous tractor was 1.5 seconds. When the CAN-based steering control system was combined with the autonomous tractor, however, control interval of the integrated system was reduced to those less than 0.05 seconds. When the autonomous tractor was operated with 1.5-s and 0.05-s control cycles at a 0.63-m/s travelling speed, the trajectories were close to straight lines for both of the control cycles. For a 1.34-m/s traveling speed, tractor trajectory was close to sine wave with a 1.5-s control cycle, but was straight line with a 0.05-s control cycle.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.4
• /
• pp.320-326
• /
• 2000

The real-time simulator of a pneumatic actuation system that is composed of differential PWM signal generator, charge solenoid valve, discharge solenoid valve, actuator, load, and rotational potentiometer is developed using a DSP board and a PC. The simulator receives the control signals from the external controller through the A/D converter, updates the state and output variables of the Pneumatic actuation system responding to the input signals every sampling time, and sends out the output signals through the D/A converter in real time. The user can observe the displacements, velocities, pressures, and mass flows representing the operation of pneumatic actuation system through the PC monitor in real time. Also the user can see the moving images between the pistons and rotating arm realistically in real time. The accuracy of the real-time simulator is verified by the good agreement of the real-time simulation results and the experimental results of the pneumatic actuation system.