The model of interacting of optical radiance with a biological fabric is calculated at the is diffusivedirected and mirror reflectances. Outcomes of calculations are resulted and guidelines for development of constructions of sensors for a photoplethysmography on the basis of the observed model are given.

Results of investigations of electrical and magnetoresistive characteristics of Si/SiO₂/Ni heterostructures obtained using the swift heavy ion track technology are presented. The presence of a positive magnetoresistance growing up with decreasing temperature and reaching 600 % at T ~ 25 K is determined. This result makes it possible to create highly-sensitive magnetic field sensor devices for space applications, which operates at a liquid hydrogen cooling. The prospects of the creation of magnetic-field sensors using alternating layers of ferromagnetic and nonmagnetic metals in the nanopores are determined. The possibility of application of the «Tunable Electronic Material in Pores in Oxide on Semiconductors» concept on this concern is demonstrated.

The hysteresis effect of the normal component of the residual magnetization field strength during local pulsed reversal magnetizing of ferromagnetic articles and using its features for quality testing of mediumcarbon steel articles hardening and tempering, articles surface-hardened layer thickness and hardness after induction hardening are presented. Design principles, structure, purposes and technical characteristics of the pulsed magnetic multiparameter analyzer IMA-M for set forth above problems of the non-destructive testing are given.

Laser spectrometers for registration of luminescent signals with nanosecond temporal resolution are presented. The versatile spectrometer is capable to operate with up to tenth of nanometer resolution in wide spectral range. The specialized spectrometer for singlet oxygen luminescence measuring in vitro and in vivo possesses unique sensitivity in the near infrared region. Experimental results confirming high technical capacities of the setups are presented.

Construction and breakdown voltage of avalanche photodiode with Read diode structure was simulated by computer. It was shown that the guard area construction composed of the metal electrode and guard rings influences on the electrical quantities of n⁺-p junction breakdown region.

The results of theoretical and experimental studies of quantum interferometer are described. The interferometer based on linear isotropic laser with displacement phased anisotropic plate inside resonator. The perspectives of usage of such resonator as a precession proximity sensor is shownThe necessity of methods and devices for modern medical linear accelerators quality control development is discussed. Quality control is the basic measure of radiation protection of the patients with malignant tumors during radiotherapy. Linear accelerators devices and systems which are influencing on accuracy of dose delivery and dose distribution within treated patients body volumes were considered. Developed methods and devices become a basis of the national protocol for medical linear accelerators quality control which will be used in all oncological clinics of Belarus Republic.

Developed the device for determining the physical and mechanical properties of elastomeric materials. In contrast to the well-known device that operates on the method of Shore, used to measure only the hardness of elastomeric materials, developed the device can measure not only hardness, but also the relative deformation of the samples made of elastomeric materials, as well as the ability of these materials to restore the original dimensions after deformation. The device has a simple design includes coaxial with the direction of the force transducer strain into an electrical signal that provides a sensitivity of at least 3 mV/μm.

The method of determination of the sharpness depth borders was improved for contemporary video technology. The computer programme for determination of corresponding video recording parameters was created.

The experimental setup for luminescence decay time measurements of rear-earth ions in condensed matters  (crystals,  glasses  and solutions)  has  been  developed.  Fluorescence decay time  of  Yb³⁺  ions  in Yb³⁺:Li₂Zn₂(MoO₄)₃ crystal was measured in the spectral range near 1 µm by using special method eliminating effects of reabsorption.

The experimental setup for thermal lens properties determination (particularly, its sign, optical power, laser rod sensitivity factors and astigmatism degree) in the anisotropic flashlamp-pumped laser crystals by a probe beam technique was developed. By means of this approach, thermal lensing measurements were performed in the N_p -cut Nd-doped potassium gadolinium tungstate (Nd:KGdW) laser crystal at the wavelength of 1,06 μm for light polarizations E || N_m и E || N_g. a

The article presents results of modelling of ring-shaped waveguide tool for ultrasonic treatment of biological materials, particularly malignant tumours, and testing of their mechanical properties. Harmonic analysis of forced flexural vibration of the waveguide using ANSYS software and APDL programming language was implemented for determination of waveguide geometric parameters providing its resonance for the given excitation frequency. The developed finite element model accounts for interaction between the waveguide and tumour tissue as well as initial prestressing of tissue radially compressed by the waveguide. Resonant curves of the waveguide in terms of its thickness and diameter are calculated and presented. Principle of application of the developed modeling technique for extraction of diagnostic data on mechanical properties of biological tissues is described.

Applicability of electronic control of laser output parameters to bulk solid-state laser sources is demonstrated. A single laser source with variable pulse duration for novel imaging and manipulation systems is presented. Stable passive mode-locking of a Cr^4+:forsterite laser using a voltage controlled p-n junction quantum dot saturable absorber was achieved. Output shortening from 17,4 to 6,4 ps near-transform limited pulses was obtained by applying reverse bias.

The problem of maintaining a constant gravitational gradient in a relatively large volume of space is considered.  This  provides  a  well  defined  input  signal  to  a  gravity  gradiometer  for  the  purpose  of  its calibration. A comparison between gravitational gradients created by straight cylinders and spheres is also provided.

The specifications of equipment produced by CAS «BMC» for metrological provision of temperature measurements are presented: low temperature thermostat «Cryostat», thermostatic device «Thermostat-A3», reference thermometer «ITE»,  measuring-calculating complex  «IST-M16». Some problems  of normative documents regulating temperature measurements are discussed. New formula approximating temperature vs. thermoelectromotive for type M thermocouple is proposed.

The concept of risks management expert system in standardization, constructed on the basis of the process approach on a modular principle is offered. The algorithm of formation of expert system module is developed, allowing to put process of working out of state standard in operated conditions on criterion of the set risk level.

The necessity of methods and devices for modern medical linear accelerators quality control development is discussed. Quality control is the basic measure of radiation protection of the patients with malignant tumors during radiotherapy. Linear accelerators devices and systems which are influencing on  accuracy of dose delivery and dose distribution within treated patients body volumes were considered. Developed methods and devices become a basis of the national protocol for medical linear accelerators quality control which will be used in all oncological clinics of Belarus Republic.

The article describes issues of operational inspection reliability assurance. Reliability is the mast important property of inspection. Reliability is defined as the probability of correct decision making during the inspection. This probability depends on the measurement error and tolerance range ratio, position of acceptance limits and technological process stability. Existing approaches to measurement tolerance design, which are also used in ГОСТ 8.051 and РД 50-98-86, do not take into consideration the influence of technological process stability on inspection reliability. Thus, these approaches are to be reconsidered.

A transducer function of probe electrometer’s primary capacitive sensor was calculated using a harmonic complex analysis technique. The obtained expression allows analyzing metrological characteristics of the circuit containing the dynamic capacitor at any values of its parameters. Study of circuit's peak-frequency and phase-frequency characteristics was held giving recommendations on using of different parts of frequency characteristic when designing measuring systems on a basis of dynamic capacitor.