575 research outputs found
Light sterile neutrino sensitivity of 163Ho experiments
We explore the sensitivity of Ho electron capture experiments to
neutrino masses in the standard framework of three-neutrino mixing and in the
framework of 3+1 neutrino mixing with a sterile neutrino which mixes with the
three standard active neutrinos, as indicated by the anomalies found in
short-baseline neutrino oscillations experiments. We calculate the sensitivity
to neutrino masses and mixing for different values of the energy resolution of
the detectors, of the unresolved pileup fraction and of the total statistics of
events, considering the expected values of these parameters in the two planned
stages of the ECHo project (ECHo-1k and ECHo-1M). We show that an extension of
the ECHo-1M experiment with the possibility to collect events will be
competitive with the KATRIN experiment. This statistics will allow to explore
part of the 3+1 mixing parameter space indicated by the global analysis of
short-baseline neutrino oscillation experiments. In order to cover all the
allowed region, a statistics of about events will be needed.Comment: 11 page
Emerging frustration effects in ferromagnetic Ce_2[Pd_{1-x}Ag_x]_2In alloys
Magnetic and thermal properties of Ferromagnetic (FM)
Ce_{2.15}(Pd_{1-x}Ag_x)_{1.95}In_{0.9} alloys were studied in order to
determine the Quantum Critical Point (QCP) at T_C => 0. The increase of band
electrons produced by Pd/Ag substitution depresses T_C(x) from 4.1K down to
T_C(x=0.5)=1.1K, with a QCP extrapolated to x_{QCP}~ 0.6. Magnetic
susceptibility from T>30K indicates an effective moment slightly decreasing
from \mu_{eff}=2.56\mu_B to 2.4\mu_B at x=0.5. These values and the
paramagnetic temperature \theta_P~ -10K exclude significant Kondo screening
effects. The T_C(x) reduction is accompanied by a weakening of the FM
magnetization and the emergence of a specific heat C_m(T) anomaly at T*~ 1K,
without signs of magnetism detected from AC-susceptibility. The magnetic
entropy collected around 4K (i.e. the T_C of the x=0 sample) practically does
not change with Ag concentration: S_m(4K)~ 0.8 Rln2, suggesting a progressive
transfer of FM degrees of freedom to the non-magnetic (NM) component. No
antecedent was found concerning any NM anomaly emerging from a FM system at
such temperature. The origin of this anomaly is attributed to an 'entropy
bottleneck' originated in the nearly divergent power law dependence for T>T*.Comment: 5 pages, 4 figures, Int. Conf. ICM 201
MRI/TRUS data fusion for brachytherapy
BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for
tumour destruction under transrectal ultrasound imaging (TRUS) control. It
requires prostate delineation from the images for dose planning. Because
ultrasound imaging is patient- and operator-dependent, we have proposed to fuse
MRI data to TRUS data to make image processing more reliable. The technical
accuracy of this approach has already been evaluated. METHODS: We present work
in progress concerning the evaluation of the approach from the dosimetry
viewpoint. The objective is to determine what impact this system may have on
the treatment of the patient. Dose planning is performed from initial TRUS
prostate contours and evaluated on contours modified by data fusion. RESULTS:
For the eight patients included, we demonstrate that TRUS prostate volume is
most often underestimated and that dose is overestimated in a correlated way.
However, dose constraints are still verified for those eight patients.
CONCLUSIONS: This confirms our initial hypothesis
Clinical Impact of Mediterranean Diet Adherence before and after Bariatric Surgery: A Narrative Review
The population suffering from obesity is rapidly increasing all over the world. Bariatric surgery has shown to be the treatment of choice in patients with severe obesity. A Mediterranean diet has long been acknowledged to be one of the healthiest dietary patterns associated with a lower incidence of many chronic diseases. The aim of the present narrative review is to summarize the existing research on the clinical impact of a Mediterranean diet before and after bariatric surgery, focusing on its effects on weight loss and improvement in comorbidities. Although the current knowledge is limited, this information could add value and emphasize the importance of adopting a Mediterranean diet before and after bariatric surgery
First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of Ho
The isotope Ho undergoes an electron capture process with a
recommended value for the energy available to the decay, , of about
2.5 keV. According to the present knowledge, this is the lowest
value for electron capture processes. Because of that, Ho is the best
candidate to perform experiments to investigate the value of the electron
neutrino mass based on the analysis of the calorimetrically measured spectrum.
We present for the first time the calorimetric measurement of the atomic
de-excitation of the Dy daughter atom upon the capture of an electron
from the 5s shell in Ho, OI-line. The measured peak energy is 48 eV.
This measurement was performed using low temperature metallic magnetic
calorimeters with the Ho ion implanted in the absorber.
We demonstrate that the calorimetric spectrum of Ho can be measured
with high precision and that the parameters describing the spectrum can be
learned from the analysis of the data. Finally, we discuss the implications of
this result for the Electron Capture Ho experiment, ECHo, aiming to
reach sub-eV sensitivity on the electron neutrino mass by a high precision and
high statistics calorimetric measurement of the Ho spectrum.Comment: 5 pages, 3 figure
Structural reorganization in a hydrogen-bonded organic framework
Self-recognition of 3,3′,5,5′-azobenzenetetracarboxylic acid drives the formation of a grid-like anionic hydrogen-bonded framework with channels occupied by organic cations. This supramolecular solid is capable of reorganizing its connectivity in the presence of specific guests into a different crystalline architecture by sequential dissolution and recrystallization
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