A white-box model of S-shaped and double S-shaped single-species population growth.

Complex systems may be mechanistically modelled by white-box modeling with using logical deterministic individual-based cellular automata. Mathematical models of complex systems are of three types: black-box (phenomenological), white-box (mechanistic, based on the first principles) and grey-box (mixtures of phenomenological and mechanistic models). Most basic ecological models are of black-box type, including Malthusian, Verhulst, Lotka-Volterra models.

A solution to the biodiversity paradox by logical deterministic cellular automata.

The paradox of biological diversity is the key problem of theoretical ecology. The paradox consists in the contradiction between the competitive exclusion principle and the observed biodiversity. The principle is important as the basis for ecological theory.

[Metrological support of clinical dosimetry].

The main requirement for the dosimetric support of radiation therapy for cancer disease is the necessity of keeping the high accuracy of dosimetric planning of radiation therapy. This dosimetric planning involves a number of components including the measurement of the supporting dose, the establishment of a correct orientation of a primary beam, the receipt of accurate data on the distribution of organs and tissues in the radiation area. In fact, in all the above components there are errors in the estimation of the basic values, which totally determine the total error in the dosimetric planning of radiation therapy.

Materials for thermoluminescent dose detectors and photon radiation energy detectors intended for intercomparison procedures of radiation therapy units.

Composite thermoluminescent (TL) materials characterized by different TL sensitivity to energy of photon radiation, namely, double-component mixtures of finely dispersed ingredients: thermoluminescent phosphor (LiF or CaSO4:Dy) and nonluminescent material (salts with various Zeff values) have been described. The TL sensitivity of such TL composites was demonstrated to depend upon Zeff values inherent to separate components and upon their concentration ratio in the mixture. Within the range of x-ray energy values from 10 to 120 keV, the LiF-based materials containing Li2CO3 as nonluminescent material were dosimetrically equivalent to soft tissues.

A new method of trabecular bone tissue dosimetry.

A new method of trabecular bone tissue dosimetry has been developed using solid-state materials. For measurement of photon radiation doses, trabecular bone was modeled by a mixture of two substances, a thermoluminescent phosphor and a nonluminophor, each of which is dosimetrically equivalent to either trabecular or red bone marrow, and each of which has a particle size range appropriate for one of the two tissue types that it represents. The ratio of components corresponds to the ratio of red bone marrow and trabecular bone as determined in actual bone samples.