71 research outputs found
Replantation of the Condylar Shoot of Fractured Temporomandular Joint of the Articular Head by TiNi-based Materials
The offered way of restoration of anatomic integrity of the articular head and of the condylar shoot of the temporomandibular joint by the way of modeling of replant at using materials of nickelid titanium alloy (TiNi) with the shape memory allows to conclude about the favorable results of rehabilitation of patients with fragmentary fractures of the articular head of the temporomandibular joint in the remote terms of observation of 8 years
Nuclear multifragmentation and fission: similarity and differences
Thermal multifragmentation of hot nuclei is interpreted as the nuclear
liquid--fog phase transition deep inside the spinodal region. The experimental
data for p(8.1GeV) + Au collisions are analyzed. It is concluded that the decay
process of hot nuclei is characterized by two size parameters: transition state
and freeze-out volumes. The similarity between dynamics of fragmentation and
ordinary fission is discussed. The IMF emission time is related to the mean
rupture time at the multi-scission point, which corresponds to the kinetic
freeze-out configuration.Comment: 7 pages, 3 Postscript figures, Proceedings of IWM 2005, Catani
Is binary sequential decay compatible with the fragmentation of nuclei at high energy?
We use a binary sequential decay model in order to describe the fragmentation
of a nucleus induced by the high energy collisions of protons with Au nuclei.
Overall agreement between measured and calculated physical observables is
obtained. We evaluate and analyse the decay times obtained with two different
parametrisations of the decay rates and discuss the applicability of the model
to high energy fragmentation.Comment: 6 pages, 4 eps figures. Small changes at the end of the text. More
arguments are given in the discussion of the time scale of the proces
Spinodal decomposition, nuclear fog and two characteristic volumes in thermal multifragmentation
Thermal multifragmentation of hot nuclei is interpreted as the nuclear
liquid-fog phase transition inside the spinodal region. The experimental data
for p(8.1GeV) + Au collisions are analyzed within the framework of the
statistical multifragmentation model (SMM) for the events with emission of at
least two IMFs. It is found that the partition of hot nuclei is specified after
expansion to a volume equal to Vt = (2.6+-0.3) Vo, with Vo as the volume at
normal density. However, the freeze-out volume is found to be twice as large:
Vf = (5+-1) Vo.Comment: 8 pages, 6 figures, to be published in Nucl.Phys.
High-resolution velocity measurements on fully identified light nuclides produced in 56Fe + hydrogen and 56Fe + titanium systems
New experimental results on the kinematics and the residue production are
obtained for the interactions of 56Fe projectiles with protons and (nat)Ti
target nuclei, respectively, at theincident energy of 1 A GeV. The
titanium-induced reaction serves as a reference case for multifragmentation.
Already in the proton-induced reaction, the characteristics of the isotopic
cross sections and the shapes of the velocity spectra of light residues
indicate that high thermal energy is deposited in the system during the
collision. In the 56Fe+p system the high excitation seems to favour the onset
of fast break-up decays dominated by very asymmetric partitions of the
disassembling system. This configuration leads to the simultaneous formation of
one or more light fragments together with one heavy residue.Comment: 24 pages, 21 figures, 1 table, this work forms part of the PhD thesis
of P.Napolitani, background information on http://www-w2k.gsi.de/kschmidt
The Kharkov X-ray Generator Facility NESTOR
WEPWA060 - ISBN 978-3-95450-122-9International audienceThe last few years the sources of the X-rays NESTOR based on a storage ring with low beam energy and Compton scattering of intense laser beam are under design and development in NSC KIPT. The main task of the project is to develop compact intense X-ray generator on the base of relatively cheap accelerator equipment and up-to-date laser technologies. The paper is devoted to description of the last results on construction and commissioning of the facility
Comparative Study of Multifragmentation of Gold Nuclei Induced by Relativistic Protons, He, and C
Multiple emission of intermediate-mass fragments has been studied for the
collisions of p, He and C on Au with the setup FASA. The mean
IMF multiplicities (for the events with at least one IMF) are saturating at the
value of for the incident energies above 6 GeV. The observed IMF
multiplicities cannot be described in a two-stage scenario, a fast cascade
followed by a statistical multifragmentation. Agreement with the measured IMF
multiplicities is obtained by introducing an intermediate phase and modifying
empirically the excitation energies and masses of the remnants.
The angular distributions and energy spectra from the p-induced collisions
are in agreement with the scenario of ``thermal'' multifragmentation of a hot
and diluted target spectator. In the case of C+Au(22.4 GeV) and
He(14.6 GeV)+Au collisions, deviations from a pure thermal break-up are
seen in the energy spectra of the emitted fragments, which are harder than
those both from model calculations and from the measured ones for p-induced
collisions. This difference is attributed to a collective flow.Comment: 33 pages 15 figures, accepted in Nucl. Phys.
Thermal multifragmentation in p + Au interactions at 2.16, 3.6 and 8.1 GeV incident energies
Multiple emission of intermediate-mass fragments has been studied for the collisions p + Au at 2.16, 3.6 and 8.1 GeV with the FASA setup. The mean IMF multiplicities for events with at least one IMF are equal to 1.7, 1.9 and 2.1 (±0.2) respectively. The multiplicity, charge distributions and kinetic energy spectra of IMF are described in the framework of a intranuclear cascade model followed by the statistical multifragmentation model. However, between the two parts of the calculation the excitation energies and the residual masses and charges are modified to take into account the losses during expansion. The results support a scenario of true thermal multifragmentation of a hot and expanded target spectator
Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling
A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems
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