In this paper, the non-destructive testing methods are analyzed in view of their usability in evalulation of the interlocking paving blocks’ compressive strength. Ultrasonic pulse method and impact method (Schmidt impact hammers) were chosen for testing. Testing methodology and way of the results processing considering requests of the national and European standards are described there. In addi...

One of the ways how to rationalize the experimental work is to put to use the non-destructive testing methods. In case of the strength testing of the various age cement specimens the usage of the ultrasonic pulse method appears to lead to decrease the necessary amount of tested samples. Application of this method requires fixed initial conditions like constant proportion of components, identica...

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of th...

The well-known thermo-elastic effect of laser irradiation can be exploited to produce strong localized stresses when an expanded, long pulse, low-intensity laser beam is used to irradiate the specimen. These stresses will produce a parametric modulation of the received ultrasonic signals, that is somewhat similar to the acousto-elastic effect often used in nonlinear ultrasonic studies. It is sh...

INTRODUCTION The use of noninvasive, acoustic methods like ultrasonometry is becoming increasingly interesting in the quantitative assessment of fracture healing. A reliable measurement technique has been described using ultrasonic transducers placed across the fracture gap. Ultrasonic image aiming is useful for accurate transducers location, on both sides of the gap. The study was designed to ...

The ultrasonic velocity, density and viscosity at 318K have been measured in the binary systems of Methyl methacrylate + Toluene and Methyl methacrylate + Dimethylacetamide. In this work an attempt has been made for the first time to investigate the behavior of binary solutions of Methylmethacrylate(MMA) in Toluene and Dimethylacetamide(DMAC) with regard to acoustical parameters such as adiabat...

This paper describes the use of air-coupled ultrasonic tomography for the simultaneous measurement of flow and temperature variations in gases. Air-coupled ultrasonic transducers were used to collect through-transmission data from a heated gas jet. A transducer pair was scanned in two-dimensional sections at an angle to the jet, and travel time and amplitude data recorded along various paths in...

This paper briefly describes the preliminary results of an experimentation aimed to test a new non-destructive methodology based on the integrated application of 3-D terrestrial laser scanning and acoustic techniques in the ultrasonic range (54 kHz) in evaluating the quality of stone materials. Our target is to evaluate the state of conservation of stone building materials by correlating ultras...

Ultrasonic irradiation of slurries produces high velocity impacts between solid metal particles that are sufficient to cause interparticle melting. Sonication of 5 mum Zn powder as a slurry in alkanes, for example, produces dense agglomerates 50 mum in diameter consisting of approximately 1000 fused particles. Particle size was found to be the most influential parameter in inducing local meltin...

Several different topological indices (the carbon number, the Wiener index, the Balaban dis­ tance sum connectivity index, the Randic molecular identification number, and the Randic molecular connectivity indices °/, 2%, 3̂ p and 3/ c) were employed in the correlation of the velocity of ultrasonic sound in a variety of alkane and alcohol species. Using linear regression analyses and published so...