AlxGa1–xSb Crystals Grown by a Modified Stepanov Technique with an Ultrasonic Effect

The ultrasonic effect on the oscillating motion and heat transfer in an oscillating heat pipe (OHP) containing acetone was investigated experimentally. The ultrasonic sound was applied to the evaporating section of the OHP by using electrically-controlled piezoelectric ceramics. The ultrasonic sound is used to generate and maintain the oscillating motion, and, thereby, heat transfer is enhanced. The heat pipe was tested with or without the ultrasonic sound. In addition, the effects of heat load, filling ratio, orientation, operating temperature, and input power from 15 W to 200 W were investigated. The experimental results demonstrate that ultrasonic sound can affect the oscillating motions and enhance the heat transfer performance of the acetone OHP. In particular, the application of the ultrasonic sound on an acetone OHP can significantly reduce the thermal resistance of the acetone OHP and enhance the heat transfer performance in a low power input region. The investigation will provide an insight into the oscillating mechanism of the acetone OHP influenced by ultrasonic sound and provide a new way to enhance the heat transfer performance of the OHP.

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Ultrasonic Effect on Phosphate Coating Formation

Bulletin of the Chemical Society of Japan ◽

10.1246/bcsj.42.2364 ◽

1969 ◽

Vol 42 (8) ◽

pp. 2364-2367 ◽

Cited By ~ 1

Author(s):

Takao Umegaki ◽

Hiroshi Ito ◽

Taijiro Okabe

Keyword(s):

Phosphate Coating ◽

Ultrasonic Effect ◽

Coating Formation

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Comparative Study of Ultrasonic Effect on Mechanical Modified Vermiculite Particles

Advanced Science Engineering and Medicine ◽

10.1166/asem.2011.1071 ◽

2011 ◽

Vol 3 (1) ◽

pp. 89-92

Author(s):

K. Barabaszová ◽

M. Valášková ◽

P. Kalivoda ◽

G. Simha Martynková

Keyword(s):

Comparative Study ◽

Ultrasonic Effect

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Ultrasonic Bubble Nucleation in Reaction Injection Moulding of Polyurethane

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/pime_proc_1994_208_068_02 ◽

1994 ◽

Vol 208 (2) ◽

pp. 121-128 ◽

Cited By ~ 11

Author(s):

W J Cho ◽

H Park ◽

J R Youn

Keyword(s):

Injection Moulding ◽

Saturation Pressure ◽

Bubble Nucleation ◽

Nucleation Theory ◽

Classical Nucleation Theory ◽

Ultrasonic Activation ◽

Cluster Theory ◽

Foam Structure ◽

Ultrasonic Effect

Ultrasonic foam processing of polyurethane for reaction injection moulding (RIM) was studied experimentally to investigate feasibility of ultrasonic bubble nucleation in polyurethane. Bubble nucleation was also studied theoretically to predict the rate of nucleation. Classical nucleation theory and cluster theory have been employed for explanation of the nucleation phenomena. A polyol resin was saturated with nitrogen at various pressures and the pressure was released slowly in order to generate supersaturated resin. Other components of the selected polyurethane system were added to the supersaturated resin and ultrasonic disruption was applied to the system producing enhanced nucleation. The ultrasonic excitation created a good foam structure even at a low saturation pressure around 0.15 MPa (1.5 atm). The effect of the ultrasonic activation on the bubble nucleation was considered and included in the nucleation theories. The cluster nucleation theory along with consideration of the ultrasonic effect predicted a higher rate of nucleation than the classical nucleation theory for the same condition.

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Ultrasonic Effect on Fabrication of Intercalated MgAl-LDH/PVA Nanocomposites via Exfoliation-Adsorption Route

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.727.532 ◽

2017 ◽

Vol 727 ◽

pp. 532-536

Author(s):

Bao Guang Li ◽

Yong Zi Xu ◽

Lu Bai ◽

Huan Dai ◽

Cai Cai Xie ◽

...

Keyword(s):

Shear Rate ◽

Double Layer ◽

Layered Double Hydroxides ◽

Ultrasonic Treatment ◽

Flow Direction ◽

Hybrid Structure ◽

High Shear ◽

Ultrasonic Effect ◽

Double Hydroxides

Glycine intercalated Mg/Al-layered double hydroxides (LDH-G)/PVA nanocomposites were prepared via exfoliation-adsorption route based on exfoliation of LDH-G in formamide. The effect of ultrasonic treatment on the fabrication of LDH-G/PVA nanocomposites was investigated. The results of XRD suggest that chains of PVA with double layer arrange into the galleries of restacking LDH platelets with the formation of intercalated-type nanocomposite. Experiments present that ultrasonic treatment on the colloid of LDH-G/PVA increases the amount of platelet which forms the intercalated phase, and improves the regularity of LDH-G arrays in the c direction. It is demonstrated the exfoliated LDH platelets orient in its normal paralleling the flow direction at the high shear rate induced by ultrasound. Simultaneously, under the enhanced temperature caused by long term of ultrasonic treatment, PVA chains extend more and the interaction between PVA chains and LDH layers is reinforced. A model was proposed for various stages of LDH platelets and PVA chains in their mixed colloid during ultrasonic treatment which describes the fabrication of improved hybrid structure.

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ULTRASONIC EFFECT ON ELECTRIC SPARK FORMING AND DEVELOPMENT IN ELECTROACOUSTIC SPRAYING

Vestnik of Don State Technical University ◽

10.23947/1992-5980-2018-18-3-306-310 ◽

2018 ◽

Vol 18 (3) ◽

pp. 306-310

Author(s):

S. B. Kudryashev ◽

A. A. Zakalyuzhny

Keyword(s):

Mathematical Model ◽

Heat Removal ◽

Ultrasonic Field ◽

Field Energy ◽

Energy Effect ◽

Factors Affecting ◽

Ultrasonic Effect ◽

Self Similar Solution ◽

Spark Channel ◽

Wear Resistance Coatings

Introduction. The electroacoustic application of wear-resistance coatings is studied. The work objective is to obtain a mathematical model of the ultrasonic effect on the formation and development of an electric spark occurring in the process of the electroacoustic sputtering.Materials and Methods. The effect of ultrasonic vibrations on the processes occurring during the formation and development of a spark discharge is analyzed; the equations of continuity, energy motion and transfer, with the ultrasonic field contribution are considered. Factors affecting the thermal conductivity and electrical conductivity of strongly ionized gas are studied. Research Results. When obtaining the model, it was assumed that the heat removal from the channel is carried out by a “clear emitter”. Then, for the channel region, a self-similar solution is made: pressure, temperature and density are constant over the cross-section, and velocity is proportional to the radius. A mathematical model that describes the processes occurring in the spark channel with the ultrasonic field energy effect is obtained.Discussion and Conclusions. On the basis of the developed model, it is specified that under the ultrasonic radiation effect, the radius and temperature of the spark channel increase, and conditions of the double ionization under high ultrasonic energy are created.

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