Ultrasonics complex vibrations with twoor three-dimensional vibration locus are effective for various applications. Various high-frequency and complex-vibration systems have been proposed and studied. The applications include ultrasonic direct welding of LSI, semiconductor chips without adhesive or solder, ultrasonic seam welding of thin metal plates, ultrasonic welding of thick metal specimens...

The effects of ultrasonic treatment (UST) on the solidification microstructure of a 35CrMo steel cast ingot were investigated. To avoid the erosion of a high-temperature melt, a T-shaped ultrasonic waveguide unit was used to introduce ultrasonic vibrations into a 35CrMo steel die casting melt. The experimental results show that the microstructure of the ingot was refined by ultrasonic treatment...

Aimed at the practical requirement of tubular joint welds inspection of offshore platform structures, the ultrasonic phased array inspection algorithm for offshore platform structures is proposed in this paper, and the ultrasonic phased array inspection system for offshore platform structures is developed. The experiment of tubular joint model is performed with the ultrasonic phased array inspe...

Several works indicate the relationship between well-solved combinatorial optimization problems and the core non-emptiness of cooperative games associated with them. In this paper, we consider the core of symmetric traveling salesman games and relate it with well-solved cases of traveling salesman problems. We show that the core of a traveling salesman game in which the distance matrix is a sym...

In this article, embedded ultrasonic sensors were prepared using 1–3-type piezoelectric composite and piezoelectric ceramic as the piezoelectric elements, respectively. The frequency bandwidth of the novel embedded ultrasonic sensors was investigated. To obtain the relationship between the receiving ultrasonic velocity and compressive strength, as well as their response signals to crack damage,...

This paper is concerned with the following two-species LotkaVolterra competition-diffusion system in the three-dimensional spatial space { ∂ ∂t u1(x, t) = ∆u1(x, t) + u1(x, t) [1− u1(x, t)− k1u2(x, t)] , ∂ ∂t u2(x, t) = d∆u2(x, t) + ru2(x, t) [1− u2(x, t)− k2u1(x, t)] , where x ∈ R3 and t > 0. For the bistable case, namely k1, k2 > 1, it is well known that the system admits a one-dimensional mo...

In this paper we design and implement an embedded surveillance system by use of ultrasonic signal coding of ultrasonic sensors with multiple pyroelectric infrared sensors (PIR) to detect an intruder in a home or a storehouse. The PIR sensors are placed on the ceiling, and the ultrasonic sensor module consists of a transmitter and a receiver which are placed in a line direction; however, ultraso...

Ultrasonic receiver circuit with Phase-locked loop 4046 Ultrasonic amplifier with high amplification factor · Transformer-coupled ultrasonic transmitter circuit. General-Purpose CMOS Rail-to-Rail Amplifier. ADP7104. 20 V, 500 mA, Low The circuit shown in Figure 1 is a completely self-contained distance sensor that utilizes an ultrasonic transmitter and sensitive analog receiver in conjunction.