Roman Gr Maev

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Quantitative evaluation of human tooth structural elements, revealed in acoustic images, has been carried out. It has been shown that tissue elements with different acoustic impedances differed in acoustic images by intensity of grey color, and also feature with different longitudinal sound velocities (C(L)). In the layer of mantle dentin, C(L) is 7% to 8%(More)
This study presents a novel approach to measure the enamel thickness potentially applicable to the veneer placing procedure. All experiments have been carried out on the extracted human teeth, using a high frequency ultrasonic transducer (50 MHz, Sonix, Springfield, VA, USA). The enamel thickness measurement results obtained with high positional accuracy by(More)
The role of non-destructive material characterization and NDT is changing at a rapid rate, continuing to evolve alongside the dramatic development of novel techniques based on the principles of high-resolution imaging. The modern use of advanced optical, thermal, ultrasonic, laser-ultrasound, acoustic emission, vibration, electro-magnetic, and X-ray(More)
Surface acoustic wave (SAW) radio-frequency identification (RFID) tags are encoded according to partial reflections of an interrogation signal by short metal reflectors. The standard encryption method involves time position encoding that uses time delays of response signals. However, the data capacity of a SAW RFID tag can be significantly enhanced by(More)
OBJECTIVES The aim of the study was to investigate the relationship between microstructure, acoustic and mechanical properties of hardened dental cement samples, prepared with different powder/water ratios. METHODS Glass-ionomer dental cement samples, prepared with a standard amount of cement powder and different amounts of water have been examined after(More)
Knowledge of periodontal anatomy is essential when performing surgical and non-surgical procedures in the field of oral healthcare. Gingival thickness (GT) is often assessed for this purpose. A dental system prototype was recently developed for quantitative, non-invasive GT assessment by high-frequency (HF) ultrasound. Laboratory trials were conducted to(More)
Up to now, biomedical imaging with ultrasound for observing a cellular tissue structure has been limited to very thinly sliced tissue at very high ultrasonic frequencies, i.e., 1 GHz. In this paper, we present the results of a systematic study to use a 150 to 200 MHz frequency range for thickly sliced biological tissue. A mechanical scanning reflection(More)
This paper examines the utilization of the time reversal matched filtering method to resolve the location of an acoustic point source beneath a skull phantom (variable thickness layer), without the removal of this layer. This acoustical process is examined experimentally in a water tank immersion system containing an acoustic source, a custom-made skull(More)
The main goal of this study is to develop a new image reconstruction approach for the ultrasonic detection of small objects (comparable to or smaller than the ultrasonic wavelength) behind an aberrating layer. Instead of conventional pulse-echo experimental setup we used through transmission, as the backscattered field after going twice through the layer(More)
We present a new wide-aperture, line-focused ultrasonic material characterization system. The foci of the transmitting and receiving transducers are located in the specimen-immersion liquid interface; and the output voltage V(x,t) of the system is recorded as a function of the lateral position of the receiving transducer. The two-dimensional spectrum of(More)