[en] The subject of this study is the radon concentrations variations, measured with a nuclear track detectors in a total of 58 premises in all 29 primary schools of 4 municipalities in the Eastern part of the Republic of Macedonia. Despite a relatively small territory, the variability of radon concentrations proved to be significant. The geometric means (geometric standard deviations) of radon concentrations in the examined municipalities were in the range from GM = 71 Bq/m 3 (GSD = 2.08) to GM = 162 Bq/m 3 (GSD = 2.69), while for the entire region it was: GM = 96 Bq/m 3 (GSD = 2.47). The influence of the geographical and geological features of the school site as well as the building characteristics on the radon variations were investigated. The analysis showed that type of municipality, building materials, basement and geology have significant effects and respectively describe 6%, 16%, 22%, 39% of the radon total variability.

[en] On-line radiation measurements over Magurele zone are necessary because of the nuclear reactor and other nuclear facilities operating within IFIN-HH. These measurements are carried out by means of a gamma probe designed in the institute. The whole surveillance system is part of RODOS network. (author)

[en] In order to describe physical reality a special (gravity-free) relativity is needed that is founded upon general non-uniform motions as they occur in our environment and hold for the non-inertial reference frame of our laboratory. Such a generalized form of special relativity can be build upon an extension, at relativistic velocities, of Maxwell-Hertz electrodynamics (MHE), which is valid for non-uniform motions, but at small velocities only. The new electromagnetic theory called (in honor to Hertz) Hertz's Relativistic Electrodynamics (HRE), is completely independent and built-up in a completely different way as regards Einstein's Special Relativity (ESR). HRE, a coordinate-free formulation does not need postulates, but confirms the constancy principle of speed of light in vacuum. All experiments of first and second order in v/c are correctly interpreted. To this theory a Hertzian kinematics and dynamics are associated. HRE with its corresponding mechanics forms Hertz's Special Relativity (HSR), as a complementary theory to ESR. According to the principle of complementarity and neglecting the gravitational effects, the Extended Special Relativity (ExSR) is a double faced theory which becomes either ESR, when the motion is inertial or HSR when the motion is non-inertial. The complementarity of both theories assumes that the two descriptions cannot be employed for the same motion, being mutually exclusive. Consequently, to every statement of one of the ExSR corresponds a complementary statement of the other ExSR. The completeness of ESR with HSR ensures an extended view over the relativity in our physical world. (author)

[en] High-spin states in ^135,136Ba, ¹³⁶La, ¹³⁷Ce, ¹³⁹Nd were populated following (HI,χn) reactions and subsequent radiation was studied using in-beam γ-ray spectroscopy methods. Level schemes with new states belonging to above mentioned nuclei are given. These nuclei situated near N = 80 have been analyzed within the framework of the interacting-boson model (IBM), applied to the description of even-even, odd-even and odd-odd nuclei. (authors)

[en] The geodesic motion on generalized Taub-NUT metrics in the presence of an electromagnetic field was analyzed. The 'non-generic symmetries' are investigated in this case. The motion on a cone and on a plane is analyzed for a particular form of F_μν. (authors)

[en] The paper describes an experimental model of a Prompt Gamma Neutron Activation Analysis that uses an Am-Be neutron source and a Ge-Li detector. The main prompt gamma peaks are recorded and by using a simple formalism, the concentrations of hydrogen, carbon, oxygen and sulfur are estimated. These data were used for determination of the caloric value of the coal sample. (authors)

[en] We study the reaction mechanisms that occur in the overlap zone for semi-peripheral heavy ion collisions at energies just above 10 MeV/A. In particular we focus on the energy sharing between the projectile-like fragments (PLF) and the target-like fragments (TLF). We show that energy sharing is correlated with the net mass transport between the two partners, according to recent experimental data. The role of fluctuations is stressed, making a comparison between dynamical and statistical variances. Statistical fluctuations seem to be prevailing at these energies. By increasing beam energy we expect that the dynamical variances become more important, due to the development of neck instabilities. In this way we predict a smooth transition from a deep-inelastic to a fragmentation reaction mechanism. (authors)

[en] The global method for all S-matrix poles identification is used in the case of a nuclear potential with Coulomb barrier. The new-class poles are identified and their properties are analyzed. The parent quasimolecular state is the new-class resonant state that corresponds to a S-matrix pole in the neighbourhood of the k_z⁽¹⁾ attractor in the k-plane. The properties of the parent quasimolecular states are deduced from the general properties of the new-class resonant states. (authors)

[en] In the framework of the Lindblad theory for open quantum systems we determine the degree of quantum decoherence of a harmonic oscillator interacting with a thermal bath. In the present paper we have studied QD with the Markovian equation of Lindblad in order to understand the quantum to classical transition for a system consisting of an one-dimensional harmonic oscillator in interaction with a thermal bath in the framework of the theory of open quantum systems based on quantum dynamical semigroups. The role of QD became relevant in many interesting physical problems from field theory, atomic physics, quantum optics and quantum information processing, to which we can add material science, heavy ion collisions, quantum gravity and cosmology, condensed matter physics. Just to mention only a few of them: to understand the way in which QD enhances the quantum to classical transition of density fluctuations; to study systems of trapped and cold atoms (or ions) which may offer the possibility of engineering the environment, like trapped atoms inside cavities, relation between decoherence and other cavity QED effects (such as Casimir effect); on mesoscopic scale, decoherence in the context of Bose-Einstein condensation. In many cases physicists are interested in understanding the specific causes of QD just because they want to prevent decoherence from damaging quantum states and to protect the information stored in quantum states from the degrading effect of the interaction with the environment. Thus, decoherence is responsible for washing out the quantum interference effects which are desirable to be seen as signals in some experiments. QD has a negative influence on many areas relying upon quantum coherence effects, such as quantum computation and quantum control of atomic and molecular processes. The physics of information and computation is such a case, where decoherence is an obvious major obstacle in the implementation of information-processing hardware that takes advantage of the superposition principle. The study of classicality using QD leads to a deeper understanding of the quantum origins of the classical world. Much work has still to be done even to settle the interpretational questions, not to speak about answering them. Nevertheless, as a result of the progress made in the last two decades, the quantum to classical transition has become a subject of experimental investigations, while previously it was mostly a domain of philosophy. The issue of quantum to classical transition points to the necessity of a better understanding of open quantum systems. The Lindblad theory provides a selfconsistent treatment of damping as a general extension of quantum mechanics

[en] In this paper we introduce a new kind of nuclear/hadronic coherent particle production mechanism in high-energy collisions called dual coherent particle emission (DCPE) which takes place when the phase velocities of the emitted particle v_Mph and that of particle source v_B1ph satisfy the dual coherence condition: v_Mph ≤ v_B1ph^-1. The general signatures of the DGPE in the nuclear and hadronic media are established and some experimental evidences are given. (authors)