596 research outputs found
Calculation of territorial risks in the explosion of transformers at the electrical substation
Работа направлена на анализ причин выхода из строя трансформаторов, расчет рисков при взрыве трансформаторов на электрической станции, что позволяет сформулировать мероприятия по повышению безопасности ее работы. The work is aimed at analyzing the causes of failure of transformers, calculating risks in the explosion of transformers at a power plant, which allows us to formulate measures to improve the safety of its work
Strong enhancement of extremely energetic proton production in central heavy ion collisions at intermediate energy
The energetic proton emission has been investigated as a function of the
reaction centrality for the system 58Ni + 58Ni at 30A MeV. Extremely energetic
protons (EpNN > 130 MeV) were measured and their multiplicity is found to
increase almost quadratically with the number of participant nucleons thus
indicating the onset of a mechanism beyond one and two-body dynamics.Comment: 5 pages, 2 figures, submitted to Physical Review Letter
Upgrade of the experimental Facilities at LNS
A feasibility study to build an helical orbit spectrometer using the SOLE magnetic field is presented in the more general context of the upgrade project of the LNS facilities. It includes the upgrade of the superconducting cyclotron to deliver high-intensity beams and the design of a new fragment separator optimized to match the beam optics of the secondary beams produced by projectile fragmentation. The main features of a helical-orbit spectrometer together with simulations performed using the SOLE magnetic field are presented and compared to the results obtained using a homogeneous solenoid field. The effects related to the geometry of the detection array and to the beam spot size on the detected impact point distribution and on the recostruction of the emission angle are also discussed
Solving the large discrepancy between inclusive and exclusive measurements of the reaction cross section at astrophysical energies
A solution of the large discrepancy existing between inclusive and exclusive
measurements of the reaction
cross section at MeV is evaluated. This problem has profound
astrophysical relevance for this reaction is of great interest in Big-Bang and
r-process nucleosynthesis. By means of a novel technique, a comprehensive study
of all existing cross section
data is carried out, setting up a consistent picture in which all the inclusive
measurements provide the reliable value of the cross section. New unambiguous
signatures of the strong branch pattern non-uniformities, near the threshold of
higher excited levels, are presented and their possible
origin, in terms of the cluster structure of the involved excited states of
and nuclei, is discussed.Comment: 5 pages, 4 figures, 1 tabl
Stabilization of linear carbon structures in a solid Ag nanoparticle assembly
Linear sp carbon nanostructures are gathering interest for the physical
properties of one-dimensional (1D) systems. At present, the main obstacle to
the synthesis and study of these systems is their instability. Here we present
a simple method to obtain a solid system where linear sp chains (i.e. polyynes)
in a silver nanoparticle assembly display a long term stability at ambient
conditions. The presence and the behavior of linear carbon is investigated by
Surface Enhanced Raman Scattering (SERS) exploiting the plasmon resonance of
the silver nanoparticles assembly. This model system opens the possibility to
investigate an intriguing form of carbon nanostructures
Prompt dipole radiation in fusion reactions
The prompt gamma ray emission was investigated in the 16A MeV energy region
by means of the 36,40Ar+96,92Zr fusion reactions leading to a compound nucleus
in the vicinity of 132Ce. We show that the prompt radiation, which appears to
be still effective at such a high beam energy, has an angular distribution
pattern consistent with a dipole oscillation along the symmetry axis of the
dinuclear system. The data are compared with calculations based on a collective
bremsstrahlung analysis of the reaction dynamics
Light harvesting of CdSe/CdS quantum dots coated with b-cyclodextrin based host-guest species through resonant energy transfer from the guests
Films of nano-hybrids based on red emitting CdSe/CdS QDs functionalized with perthiolated \u3b2-cyclodextrin hosting a green emitting nitrobenzoxadiazole derivative show emission harvested by the host\u2013guest organic system through resonant energy transfer from the organic host\u2013guest species to the QD
Correlations in Nuclear Arrhenius-Type Plots
Arrhenius-type plots for multifragmentation process, defined as the
transverse energy dependence of the single-fragment emission-probability,
-ln(p_{b}) vs 1/sqrt(E_{t}), have been studied by examining the relationship of
the parameters p_{b} and E_{t} to the intermediate-mass fragment multiplicity
. The linearity of these plots reflects the correlation of the fragment
multiplicity with the transverse energy. These plots may not provide thermal
scaling information about fragment production as previously suggested.Comment: 12 pages, Latex, 3 Postscript figures include
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