• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1259-1263
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• 2004

In this paper, the optimum design of ultrasonic dry cleaning head was investigated. The transducer instead of mechanical dynamic structure was used to generate ultrasonic wave and the horn-shape amplifier was utilized to solve the energy decaying problem of ultrasonic wave with propagating it through the media. The analyses of ultrasonic wave and a fluid for the selected structure of a cleaning head were carried out using SYSNOISE and ANSYS simulators, respectively. Based on simulator results, the distance between a horn and the substrate of 4 mm and the horn diameter of 10 mm were determined to maximize the energy of ultrasonic waves. The cooling structure was also considered to reduce the heat from the transducer and the horn. The equivalent circuit for the fabricated horn was deduced from HP4194A impedance/gain/phase analyzer and the frequency of an ultrasonic wave of 20.25 kHz was confirmed using the parameters of the equivalent circuit.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.418-420
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• 2005

This paper proposed ultrasonic distance measurement module development for correct distance detection with collision escaping or obstacle of mobile robot is traveling self-regulation. Representative ultrasonic module applied in existing was Polaroid company's 6500 series and Devantech company's SRF04/SRF08 series. This ultrasonic sensors are corrupted by systematic errors due mainly to the dependency of sound speed upon surrounding conditions and random errors of uncertain origin. Therefore Ultrasonic distance detecting means of error compensation method and high definition, narrow beam angle, board area distance detecting means to apply to ultrasonic mobile robot control urgently need. In this paper use internal type temperature compensation method to improve problem of ultrasonic distance measurement method instead of that volume that have shortcoming of used correct temperature compensation methods applied big addition device. Compensate error by environment change of temperature. Humidity density etc. and is applicable to mobile robot offering various interface and real-time processing developed possible distance measurement module.

• Journal of the Korean institute of surface engineering
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• v.27 no.2
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• pp.109-117
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• 1994

Effect of ultrasonic agitation on the contact properties was studied in Ni electroless plating and Pd activation. P-type Si bare wafers were used as substrate and DMAB was used as reducing agent due to its good electrical properties, solderability and compatibility to substrate. In activation, high density Pd nuclei of small size were formed during ultra-sonic agitation compared to that of no stirring. In electroless plating, the plating rate was enhanced by 30∼90% by using ultrasonic agitation. In elecrtoless plating, inhibitor is the most effective additives in ultrasonic agitation. In this experi-ment, thiourea was used as inhibitor. The less the amount of the inhibitor, the more ultrasonic agitation efficiency. It is confirmed by SEM that Ni-B films formed by ultrasonic were coarser, less porous, and denser than those of no stirring. In ultrasonic agitation, boron content of the films was more than those of no stirring. In this case, the more DMAB concentration, the higher the temperature, the less pH, the more boron content. Resistivity of the films formed by ultrasonic agitation was higher than that of no strirring. As the content of boron was increased, the resistivity of the films was increased exponentially.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1463-1471
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• 2017

In order to monitor the pipe thinning caused by flow-accelerated corrosion (FAC) that occurs in coolant piping systems, a shear horizontal ultrasonic pitch-catch waveguide technique was developed for accurate pipe wall thickness monitoring. A clamping device for dry coupling contact between the end of the waveguide and pipe surface was designed and fabricated. A computer program for multi-channel on-line monitoring of the pipe thickness at high temperature was also developed. Both a four-channel buffer rod pulse-echo type and a shear horizontal ultrasonic waveguide type for high-temperature thickness monitoring system were successfully installed to the test section of the FAC proof test facility. The overall measurement error can be estimated as ${\pm}10{\mu}m$ during a cycle from room temperature to $200^{\circ}C$.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.5
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• pp.590-599
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• 2003

In this study. object transport method based on ultrasonic flexural vibration is presented. Ultrasonic vibration generates ultrasonic traveling waves on the surface of elastic medium. Objects are transported through the interaction with traveling waves propagating in medium. Two types of transport methods are studied： frictional drive and acoustic levitation. With frictional drive, objects are transported in contact with the beam in the opposite direction of wave propagation whereas with acoustic levitation, objects are acoustically levitated above the beam surface and transported in the wave propagation direction. Transport characteristics are experimentally investigated using objects of different shapes and sizes. The transition from acoustic levitation mode to frictional drive mode is also examined. and it is found to occur when the ratio of mass to area of an object exceeds the threshold ratio of mass to area. It is envisaged that this feasibility study will serve as a stepping-stone for ultrasonic vibration to become an effective industrial material handling device in the future.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.5 s.98
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• pp.564-570
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• 2005

This paper presents some results of research for applying ultrasonic cleaning to an interior wall of cylindrical pipe. As the cleaning is achieved better for higher sound pressure, ultrasonic sound field in a cylindrical container is considered. The paper identifies nonuniform sound field established by the radiation of a cylindrical transducer driven at resonant frequency, Numerical analysis predicts the sound pressure distribution, and experiment verifies the trend of analysis results. Experiment observes the cleaning effect, and this paper suggests the possibility of using a cylindrical ultrasonic cleaning device.

• Journal of ILASS-Korea
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• v.3 no.4
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• pp.50-57
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• 1998

The utilization of resonance should be considered to get the maximum effect of ultrasonic to atomize liquid. The ultrasonic generator, transducer, horn, and all attached parts are used to produce the resonance, and specially the characteristics of liquids such as liquid load, property, and etc., for the liquid atomization affinity are considered. In this study, the variable device of liquid load was made and distilled water and city water selected as experimental liquids were sprayed by a twin-fluid spray method and their diameters, distributions, and spray quantum of spray droplets were measured by the light scattering system. And all data were observed, compared and considered relatively. In results, a lot of phenomena of liquid atomization affinity by ultrasonic appeared in accordance with liquid loads, namely head h.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1029-1032
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• 2008

Nowadays, the necessity of the NDT technique for concrete structure has been increased due to maintenance of infra-structure. With this reason, NDT detecting technique has been considered as a effective maintenance method to prevent the rapid degradation of the infra-structure. In this study, to investigate the internal defect of concrete structure, ultrasonic detection device and radar equipment was applied then tested in laboratory and field. In the result of the experimental test, the internal cavity and steel arrangement can be detected and it was possible to adopt the ultrasonic detection method to the maintenance of concrete structure. And an algorithm for performing the maintenance procedure of concrete structure applying ultrasonic detection device and radar equipment was developed and suggested in this study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.241-241
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.05a
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• pp.89-89
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• 1994