Electrical capacitance tomography (ECT) is a technique of imaging the distribution of permittivity inside an object under test. Capacitance is measured between the electrodes surrounding the object, and the image is reconstructed from these data by solving the inverse problem. Although both sinusoidal excitation and pulse excitation are used in the sensing circuit, only the AC method is used to measure both components of complex capacitance. In this article, a novel method of complex capacitance measurement using pulse excitation is proposed for ECT. The real and imaginary components are calculated from digital samples of the integrator response. A pulse shape in the front-end circuit was analyzed using the Laplace transform. The numerical simulations of the electric field inside the imaging volume as well as simulations of a pulse excitation in the front-end circuit were performed. The calculation of real and imaginary components using digital samples of the output signal was verified. The permittivity and conductivity images reconstructed for the test object were presented. The method enables imaging of permittivity and conductivity spatial distributions using capacitively coupled electrodes and may be an alternative measurement method for ECT as well as for electrical impedance tomography.

Praca omawia metody wykrywania i ilościowego oznaczania związków cyjanogennych w roślinach. Charakteryzuje właściwości i znaczenie toksykologiczne oraz farmakologiczne wybranych substancji cyjanogennych.

The article concerns the research on the properties of core-shell superparamagnetic nanoparticles in the context of their use in medicine for diagnostics and therapy. The article presents a system for impedance (AC) spectroscopy of nanoparticles with a new arrangement of receive coils. A significant modification was the position of the reference coil in relation to the receive coils as well as the method of winding and routing the wires on the carcass. The 3D printing technique was used in the production of the measuring coil system. The aim of the work was to experimentally verify the developed measurement system and analyze its properties. The system tests were carried out at low frequencies ranging from 2 to 50 kHz. Complex magnetic susceptibility was measured for superparamagnetic iron oxide nanoparticles in polymer shells in a physiological saline solution. The obtained results confirmed the relevance of the concept of the measurements. In summary, the observed properties of the realized system are discussed and further directions of its development are proposed.

A sim ple sta tis ti cal the ory of ra di a tion dam age of semi con duc tor mem ory has been constructed. The ra di a tion dam age of EPROM mem ory has been in ves ti gated. The mea sured num ber of dam aged bytes is sig nif i cantly lower than the ex pected num ber re sult ing from the purely ran dom dis tri bu tion of the dam aged bits. In this way it has been proven that there is a cor re la tion be tween the fail ures of in di vid ual mem ory bits which are lo cated in the same byte.

Single photon counting system for biomedical applications was designed and tested. Examination ofchanges ofan optical signal on a patient's head during stimulation tests (finger taping) was made by the elaborated system.