Alexander N. Kalashnikov

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We investigated the possibility of substantially reducing the cost of minimally invasive ultrasonic non-destructive evaluation (NDE) of liquids, in particular, temperature sensing, using inexpensive narrowband transducers. Although designed for operation in air, ultrasonic transducers enclosed in an aluminum case could be submerged in water and were found(More)
Polymeric tissue scaffolds are central to many regenerative medicine therapies offering a new approach to medicine. As the number of these regenerative therapies increases there is a pressing need for an improved understanding of the methods of scaffold fabrication. Of the many approaches to processing scaffolds, supercritical fluid fabrication methods have(More)
Experiments conducted in several countries have shown that the improvement of machining quality can be promoted through conversion of the cutting process into one involving controllable high-frequency vibration at the cutting zone. This is achieved through the generation and maintenance of ultrasonic vibration of the cutting tool to alter the fracture(More)
This paper presents an analysis of the error generation mechanisms that affect the accuracy of measurements of ultrasonic wave attenuation coefficient and phase velocity as functions of frequency. In the first stage of the analysis we show that electronic system noise, expressed in the frequency domain, maps into errors in the attenuation and the phase(More)
This paper proposes a novel architecture for a data acquisition system intended to support the next generation of ultrasonic imaging instruments operating at or above 100 MHz. Existing systems have relatively poor signal-to-noise ratios and are limited in terms of their maximum data sampling rate, both of which are improved by a combination of embedded(More)
This paper focuses on the analysis of frame jitter and the impact of data acquisition architecture on the associated disturbances to the acquired record. Frame jitter leads to the same random shift of all samples in an acquired record. It results in errors in the estimates of time intervals, and makes consecutive records slightly incoherent compromising(More)
This paper describes an approach for the development of an embedded web server that facilitates a remote access for a laboratory experiment for distance learning purposes. The experiment involves measurement of a voltampere characteristic of a semiconductor diode by setting the voltages applied to it remotely over the Internet. The learner observes two(More)
Online ultrasonic monitoring of aqueous solutions involves acquisition of an ultrasonic waveform either propagated through the solution or reflected from a reflector placed inside it. Most conventional ultrasonic instruments upload the waveform to a separate computer which calculates from this waveform, e.g., the propagation delay and the attenuation(More)