Virgil-Florin Duma

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We analyze the three most common profiles of scanning functions for galvanometer-based scanners (GSs): the sawtooth, triangular and sinusoidal functions. They are determined experimentally with regard to the scan parameters of the input signal (i.e., frequency and amplitude). We study the differences of the output function of the GS measured as the(More)
Three simple and low-cost configurations of handheld scanning probes for optical coherence tomography have been developed. Their design and testing for dentistry applications are presented. The first two configurations were built exclusively from available off-the-shelf optomechanical components, which, to the best of our knowledge, are the first designs of(More)
A routine cavity preparation of a tooth may lead to opening the pulp chamber. The present study evaluates quantitatively, in real time, for the first time to the best of our knowledge, the drilled cavities during dental procedures. An established noninvasive imaging technique, Optical Coherence Tomography (OCT), is used. The main scope is to prevent(More)
The galvanometer-based scanners (GS) are optomechatronic devices with a wide range of applications, from industrial to biomedical imaging. They are driven with periodical and time variable signals - especially sawtooth, triangular, sine wave or signals with special variations. We approach in this paper the rejection of the effect of disturbances in order to(More)
We demonstrate the capability of optical coherence tomography (OCT) to perform topography of metallic surfaces after being subjected to ductile or brittle fracturing. Two steel samples, OL 37 and OL 52, and an antifriction Sn-Sb-Cu alloy were analyzed. Using an in-house-built swept source OCT system, height profiles were generated for the surfaces of the(More)
We study experimentally the effective duty cycle of galvanometer-based scanners (GSs) with regard to three main parameters of the scanning process: theoretical/imposed duty cycle (of the input signal), scan frequency, and scan amplitude. Sawtooth and triangular input signals for the device are considered. The effects of the mechanical inertia of the(More)
Antibodies against rat myocardium were studied by means of histoimmunfluorescence (indirect technique) in 32 rheumatic fever patients. Antibodies were found in 54% of the cases without carditis or active rheumatic valvulitis and in 83% of those with carditis. The fluorescent patterns observed were : sarcolemmal, sarcoplasmic (intermyofibrillar) and smooth(More)
Two procedures for isolation of lactoferrin are described using ion exchange and immunoaffinity chromatography. Electrophoretic mobility, molecular mass, isoelectric point and other physico-chemical properties of the antigen were studied. Immunodiffusion and immunoperoxidase techniques exhibited presence of the antigen in some tissues containing glandular(More)
We analyze the vignetting phenomenon both for optical systems with objects placed at finite distances and for systems with objects at infinity. Four of the possible definitions of the vignetting coefficient k, only two of them existing in the literature, are discussed. We propose two new definitions, i.e., a nonlinear geometric coefficient that is, in part,(More)