351 research outputs found
Contribution à l'étude des variations de la composition du lait et leurs conséquences en technologies laitières
Le lait est une matière première aux ressources considérables mais dont la composition est variable. Le but de cette thèse est d'étudier les variations des différents composants du lait en fonction de facteurs intrinsèques (liés à l'animal : race, stade de lactation,...) et des facteurs extrinsèques (liés à l'environnement : alimentation,saison, technique de récolte et de traitement du lait) de la production laitière. Cette étude permet en parallèle d'approcher les différentes techniques utilisées par les intervenants de la filière : éleveurs, industriels laitiers, qui permettent de fabriquer, à partir d'une matière première variable, des produits laitiers aux caractéristiques constantes et répondant aux exigences des consommateurs. Seront en particulier envisagés, l'importance des recherches en matière de génétique animale pour améliorer le rendement de la lactation, et l'utilisation, en industrie laitière, des techniques de séparation par membrane pour séparer les différents constituants du lait
Strong polarization of the residual nucleus in a heavy-ion induced transfer reaction
A strong polarization of 20Ne levels has been observed in the 16O(16O, 12C)20Ne* reaction along an axis perpendicular to the reaction plane. This polarization differs from that reported in the (7Li, t) reaction, when the same nuclear levels were populated. D.W.B.A. calculations which fitted both angular distributions and polarization in the (7Li, t) reaction and which can also describe the (16O, 12C) angular distributions fail to reproduce the associated 20Ne* polarization
Low Energy States of : Elements on the Doubly-Magic Nature of Ni
Excited levels were attributed to Ga for the first time
which were fed in the -decay of its mother nucleus Zn produced in
the fission of U using the ISOL technique. We show that the structure
of this nucleus is consistent with that of the less exotic proton-deficient
N=50 isotones within the assumption of strong proton Z=28 and neutron N=50
effective shell effects.Comment: 4 pages, REVTeX 4, 5 figures (eps format
Discovery of the Vanadium Isotopes
Twenty-four vanadium isotopes have so far been observed; the discovery of
these isotopes is discussed. For each isotope a brief summary of the first
refereed publication, including the production and identification method, is
presented.Comment: to be published in At. Data. Nucl. Data Table
Excited states of 19N and 21O
(18O, 19N) and (18O, 21O) nuclear reactions on a 18O target provide measurements of excited state energies at 1.12 and 1.59 MeV for 19N and at 1.35 and 3.00 MeV for 21O. The 19N mass is remeasured as 15.856 ± 0.050 MeV
Discovery of the Cobalt Isotopes
Twenty-six cobalt isotopes have so far been observed; the discovery of these
isotopes is discussed. For each isotope a brief summary of the first refereed
publication, including the production and identification method, is presented.Comment: to be published in Atomic Data and Nuclear Data Table
On the discovery of doubly-magic Ni
The paper reports on the first observation of doubly-magic Nickel-48 in an
experimental at the SISSI/LISE3 facility of GANIL. Four Nickel-48 isotopes were
identified. In addition, roughly 100 Nickel-49, 50 Iron-45, and 290 Chromium-42
isotopes were observed. This opens the possibility to search for two-proton
emission from these nuclei.Comment: 4 pages, 3 figures, accepted for publication in Phys. Rev. Let
Collapse of the N=28 shell closure in Si
The energies of the excited states in very neutron-rich Si and
P have been measured using in-beam -ray spectroscopy from the
fragmentation of secondary beams of S at 39 A.MeV. The low 2
energy of Si, 770(19) keV, together with the level schemes of
P provide evidence for the disappearance of the Z=14 and N=28
spherical shell closures, which is ascribed mainly to the action of
proton-neutron tensor forces. New shell model calculations indicate that
Si is best described as a well deformed oblate rotor.Comment: 4 pages, 3 figures, accepted for publication in Phys. Rev. let
Release properties of UC and molten U targets
The release properties of UC and molten U thick targets associated with a Nier- Bernas ion source have been studied. Two experimental methods are used to extract the release time. Results are presented and discussed for Kr, Cd, I and Xe
- …