Synthesis and characterization of multilayered BaTiO3/NiFe2O4 thin films

Presented research was focused on the fabrication of multiferroic thin film structures, composed of ferrielectric barium titanate perovskite phase and magnetostrictive nickel ferrite spinel phase. The applicability of different, solution based, deposition techniques (film growth from solution, dip coating and spin coating) for thefabrication of multilayered BaTiO3 /NiFe2O4 thin films was investigated. It was shown that only spin coating produces films of desired nanostructure, thickness and smooth and crackfree surfaces

EVALUATION OF ENERGY STRESS ON LINE ARRESTERS

Line Surge Arresters (LSAs) are efficient means for the improvement of the lightning performance of transmission lines. Determination of optimal LSA number, location and rating is important for the improvement of the reliability and availability of a transmission system. In selection of the LSA special attention should be paid to their energy stress which depends on complex interactions between the arrester locations, grounding, shielding and the local lightning environment. LSAs experience higher energy stress compared to station arresters, because the incoming surge to a station is limited by insulator flashover on the transmission line and impulse corona. In this paper calculations of energy stresses were carried out for a double-circuit 220 kV line with a single shielding wire. Parametric studies were conducted in which arrester discharge energy was a function of: time to half value of stroke current, number of towers with arresters, footing resistance, span length and angle of power frequency voltage. Arrester energy stress is analyzed in case of stroke to tower and shielding failure. From conducted analysis it can be concluded that energy stress on LSAs is lower for shorter span lengths. Tower footing resistance has only minor effect on the discharge energy. Arrester discharge energy strongly depends on time to half of the stroke current, number of towers with installed arresters and angle of power frequency voltage

Experimental study of high-lying states in ²⁸Mg using the resonant elastic scattering of α particles

International audienceThe excitation function of Mg28 above the α-decay threshold has been measured for the first time using the resonant scattering of α particles with the technique of a thick target in inverse kinematics. Thirteen new states are reported between Ex=15.5 and Ex=20.5 MeV, and suggestions for spin-parity assignments are given for two of these. Calculations of the branching ratio to α decay for these states as well as comparison of the measured cross sections to calculations suggest that α+Neg.s.24 clustering is not dominant in this energy regime

Structure of 24Mg excited states and their influence on nucleosynthesis

The main idea of the two presented experiments is to study the decay of resonances in 24Mg at excitation energies above the 12C+12C decay thresh- old, in the astrophysical energy region of interest. The measurement of the 12C(16O,α)24Mg* reaction was performed at INFN-LNS in Catania. Only the α+20Ne decay channel of 24Mg is presented here, because it was a motivation for conducting a new experiment, a study of the 4He(20Ne,4He)20Ne reaction, performed at INFN-LNL in Legnaro. Some preliminary results of this measurement are also presented

Analysis of states in ¹³C populated in ⁹Be + ⁴He resonant scattering

Measurements of 9Be+α resonant scattering have been performed using the thick-target approach with a 4He gas volume and a large area silicon strip detector. 9Be beam energies in the range 12 to 21.4 MeV were used to measure the 13C excitation energy spectrum between 13.2 and 16.2 MeV. An R-matrix analysis has been performed to characterize the spins and widths of 13C resonances, some of which have been proposed to be associated with a 3α+n molecular band

13C+4He resonant elastic scattering on a thick gas target

Resonant elastic scattering of 13C on a thick 4He target has been measured. Reaction products from 13C(4He, 4He) were detected at several beam energies and gas pressures. Raw yield was efficiency corrected using Monte Carlo simulations and an averaged yield spectrum was produced. The observed peaks correspond well to the previously measured elastic scattering data

Study of 24Mg resonances relevant to carbon burning nucleosynthesis

We have studied the decays of the resonances of 24Mg at excitation energies 1–6 MeV above the 12C+12C decay threshold, using the 12C(16O,α)24Mg* reaction at E(16O) = 94 MeV. Some preliminary results are presented and further analysis is in progress

The thick target inverse kinematics technique with a large acceptance silicon detector array

An experimental technique for studying elastic scattering using a thick gas target is described, with a measurement of the α(24Ne, α) reaction used as an example. Advantages such as ease, detector efficiency, and the possibility of measuring the cross section at 180° in the centre-of-mass are discussed. It is shown that a resolution of tens of keV is practical at zero degrees, and that the dominant contribution to the resolution for large angles is angular straggling of the beam in the entrance window. The use of helium gas as the target allows direct measurement of a-cluster states

NAČINI OBAVLJANJA KOMUNALNIH DJELATNOSTI U SUSTAVU KOMUNALNOG GOSPODARSTVA

Komunalno gospodarstvo obuhvaća dio gospodarstva koji se odnosi na pružanje usluga u komunalnim djelatnostima, koje se zbog svoje posebnosti moraju posebno pravno odrediti i urediti unutar tog područja. Posebnost komunalnih djelatnosti očituje se u vrsti usluga koje predstavljaju temelj urbanog življenja. Lokalna vlast, kao dio ukupnog sustava vlasti koja je najbliža građanima, u mogućnosti je pratiti i prepoznati potrebe građana i na vrijeme reagirati kako bi se potrebe građana zadovoljile u najvećoj mogućoj mjeri. To između ostalog znači stalnu brigu o tome da komunalne djelatnosti, koje se obavljaju kao javna služba i koje su prijeko potrebne kako bi se zadovoljile opće društvene potrebe, funkcioniraju uredno. Cilj ovoga rada je odrediti pojam komunalnih djelatnosti i dati pregled načina obavljanja komunalnih djelatnosti kako je to propisano odredbama Zakona o komunalnom gospodarstvu

EVALUATION OF ENERGY STRESS ON LINE ARRESTERS

Line Surge Arresters (LSAs) are efficient means for the improvement of the lightning performance of transmission lines. Determination of optimal LSA number, location and rating is important for the improvement of the reliability and availability of a transmission system. In selection of the LSA special attention should be paid to their energy stress which depends on complex interactions between the arrester locations, grounding, shielding and the local lightning environment. LSAs experience higher energy stress compared to station arresters, because the incoming surge to a station is limited by insulator flashover on the transmission line and impulse corona. In this paper calculations of energy stresses were carried out for a double-circuit 220 kV line with a single shielding wire. Parametric studies were conducted in which arrester discharge energy was a function of: time to half value of stroke current, number of towers with arresters, footing resistance, span length and angle of power frequency voltage. Arrester energy stress is analyzed in case of stroke to tower and shielding failure. From conducted analysis it can be concluded that energy stress on LSAs is lower for shorter span lengths. Tower footing resistance has only minor effect on the discharge energy. Arrester discharge energy strongly depends on time to half of the stroke current, number of towers with installed arresters and angle of power frequency voltage