501 research outputs found
Food, nutrition & behaviour : research for healthy eating, healthy living
This brochure illustrates this range of research activities in the domain of food and nutrition, lifestyle and health. It does so by providing examples of collaboration of Wageningen UR with partners in the public and private sector
Spin polarization induced by optical and microwave resonance radiation in a Si vacancy in SiC: A promising subject for the spectroscopy of single defects
Depending on the temperature, crystal polytype, and crystal position, two opposite schemes have been observed for the optical alignment of the populations of spin sublevels in the ground state of a Si vacancy in SiC upon irradiation with unpolarized light at frequencies of zero-phonon lines. A giant change by a factor of 2-3 has been found in the luminescence intensity of zero-phonon lines in zero magnetic field upon absorption of microwave radiation with energy equal to the fine-structure splitting of spin sublevels of the vacancy ground state, which opens up possibilities for magnetic resonance detection at a single vacancy. © 2007 Pleiades Publishing, Ltd
A model for two-proton emission induced by electron scattering
A model to study two-proton emission processes induced by electron scattering
is developed. The process is induced by one-body electromagnetic operators
acting together with short-range correlations, and by two-body
currents. The model includes all the diagrams containing a single correlation
function. A test of the sensitivity of the model to the various theoretical
inputs is done. An investigation of the relevance of the currents is
done by changing the final state angular momentum, excitation energy and
momentum transfer. The sensitivity of the cross section to the details of the
correlation function is studied by using realistic and schematic correlations.
Results for C, O and Ca nuclei are presented.Comment: 30 pages, 18 figures, 3 table
The Ultimate Fate of Supercooled Liquids
In recent years it has become widely accepted that a dynamical length scale
{\xi}_{\alpha} plays an important role in supercooled liquids near the glass
transition. We examine the implications of the interplay between the growing
{\xi}_{\alpha} and the size of the crystal nucleus, {\xi}_M, which shrinks on
cooling. We argue that at low temperatures where {\xi}_{\alpha} > {\xi}_M a new
crystallization mechanism emerges enabling rapid development of a large scale
web of sparsely connected crystallinity. Though we predict this web percolates
the system at too low a temperature to be easily seen in the laboratory, there
are noticeable residual effects near the glass transition that can account for
several previously observed unexplained phenomena of deeply supercooled liquids
including Fischer clusters, and anomalous crystal growth near T_g
First measurements of the ^16O(e,e'pn)^14N reaction
This paper reports on the first measurement of the ^16O(e,e'pn)^14N reaction.
Data were measured in kinematics centred on a super-parallel geometry at energy
and momentum transfers of 215 MeV and 316 MeV/c. The experimental resolution
was sufficient to distinguish groups of states in the residual nucleus but not
good enough to separate individual states. The data show a strong dependence on
missing momentum and this dependence appears to be different for two groups of
states in the residual nucleus. Theoretical calculations of the reaction using
the Pavia code do not reproduce the shape or the magnitude of the data.Comment: 10 pages, 11 figures, 2 tables, Accepted for publication in EPJ
Silicon vacancy in SiC as a promising quantum system for single-defect and single-photon spectroscopy
Results of experiments are presented that suggest that the Si vacancy in SiC is a promising quantum system for single-defect and single-photon spectroscopy in the infrared region. The investigation was carried out with electron paramagnetic resonance (EPR), zero-field optically detected magnetic resonance (ODMR), direct-detection EPR (DD-EPR), and high-resolution fluorescence-excitation spectroscopy. Depending on the temperature, crystal polytype, and crystal position, two opposite schemes have been observed for the optical alignment of the populations of the spin sublevels of the high-spin ground state of the Si vacancy in SiC upon irradiation with unpolarized light at the zero-phonon lines (ZPLs). A giant change has been found in the luminescence intensity of the ZPLs in zero magnetic field upon the application of resonant microwaves which induce transitions between the spin sublevels of the vacancy ground state thus opening the possibility for magnetic-resonance detection of a single vacancy. The optical alignment of the populations of the spin sublevels in the ground state of the Si vacancy was shown with DD-EPR. Surprisingly narrow ZPLs of Si vacancies with a width less than 0.05 meV have been observed which seem to be the narrowest detected so far in SiC. © 2011 American Physical Society
Investigation of the Exclusive 3He(e,e'pp)n Reaction
Cross sections for the 3He(e,e'pp)n reaction were measured over a wide range
of energy and three- momentum transfer. At a momentum transfer q=375 MeV/c,
data were taken at transferred energies omega ranging from 170 to 290 MeV. At
omega=220 MeV, measurements were performed at three q values (305, 375, and 445
MeV/c). The results are presented as a function of the neutron momentum in the
final-state, as a function of the energy and momentum transfer, and as a
function of the relative momentum of the two-proton system. The data at neutron
momenta below 100 MeV/c, obtained for two values of the momentum transfer at
omega=220 MeV, are well described by the results of continuum-Faddeev
calculations. These calculations indicate that the cross section in this domain
is dominated by direct two-proton emission induced by a one-body hadronic
current. Cross section distributions determined as a function of the relative
momentum of the two protons are fairly well reproduced by continuum-Faddeev
calculations based on various realistic nucleon-nucleon potential models. At
higher neutron momentum and at higher energy transfer, deviations between data
and calculations are observed that may be due to contributions of isobar
currents.Comment: 14 pages, 1 table, 17 figure
Chromosome 1p13 genetic variants antagonize the risk of myocardial infarction associated with high ApoB serum levels
PMCID: PMC3480949This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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