Time filter

Source Type

Castel Guelfo di Bologna, Italy

Tino G.M.,University of Florence | Rosi G.,University of Florence | Sorrentino F.,University of Florence | Cacciapuoti L.,European Space Agency | Prevedelli M.,DellUniversity Bologna
2013 Joint European Frequency and Time Forum and International Frequency Control Symposium, EFTF/IFC 2013 | Year: 2013

We report on the current performance of our atom interferometry gravity gradiometer. After careful elimination of the main sources of fluctuations and biases in the atom interferometer, we achieve a sensitivity of 3×10 -9 g per second to differential gravity; by modulating the position of a set of source masses, we achieve a relative statistical uncertainty of 1.1 × 10-4 to the gravitational constant G. © 2013 IEEE.

Capozziello S.,University of Naples Federico II | Capozziello S.,Compl University Of Monte gelo | Capozziello S.,National Institute of Nuclear Physics, Italy | Galluzzi V.,DellUniversity Bologna | And 3 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

By considering f(R) gravity models, the cosmic evolution is modified with respect to the standard ΛCDM scenario. In particular, the thermal history of particles results is modified. In this paper, we derive the evolution of relics particles (weakly interacting massive particles) assuming a reliable f(R) cosmological solution and taking into account observational constraints. The connection to the PAMELA experiment is also discussed. Results are consistent with constraints coming from BICEP2 and PLANCK experiments. © 2015 American Physical Society.

Amelino-Camelia G.,University of Rome La Sapienza | Amelino-Camelia G.,National Institute of Nuclear Physics, Italy | Bianco S.,University of Rome La Sapienza | Bianco S.,National Institute of Nuclear Physics, Italy | And 4 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Theories involving curved momentum space, which recently became a topic of interest in the quantum-gravity literature, can, in general, violate many apparently robust aspects of our current description of the laws of physics, including relativistic invariance, locality, causality, and global momentum conservation. Here, we explore some aspects of the pathologies arising in generic theories involving curved momentum space for what concerns causality and momentum conservation. However, we also report results suggesting that when momentum space is maximally symmetric, and the theory is formulated relativistically, most notably including translational invariance with the associated relativity of spacetime locality, momentum is globally conserved and there is no violation of causality. © 2015 American Physical Society.

Rinaldi M.F.,Radiologia III | Rinaldi M.F.,University of Bologna | Bartalena T.,University of Bologna | Braccaioli L.,Radiologia III | And 8 more authors.
Radiologia Medica | Year: 2010

Purpose. This study was done to evaluate the variability of semiautomated volume measurements of solid pulmonary nodules between two different versions of the same volumetric software. Materials and methods. The volumes of 100 solid intraparenchymal nodules (mean volume 88.10 mm 3; range 7.36-595.25 mm 3) studied with the same multidetector computed tomography (MDCT) protocol were determined using two different versions of the same volumetric software (LungCARE 2006G and LungCARE 2007S). The 2006G version is based on a single-segmentation algorithm, whereas the newer version features two algorithms: SmallSizeNodule and AllSizeNodule. The results obtained with the 2006G version were compared with those of the 2007S version with the SmallSizeNodule algorithm, as recommended by the user manual. In addition, we compared the volumetric measurements obtained by the two different algorithms of the 2007S version. Results. The 2006G version and the 2007S version with the SmallSizeNodule algorithm agreed in only two of 100 cases and showed a mean variability of 1.66% (range 0%-8.78%). A more significant volumetric discrepancy was observed between the two different algorithms of the 2007S version, with the AllSizeNodule algorithm providing on average larger volumes (mean variability 71.08%; range 6.02%-218.80%) than SmallSizeNodule. Volume discrepancies were more pronounced in the subgroups of smaller nodules in all comparisons. Conclusions. There is variability also in the results provided by different versions of the same volumetric software, and this may affect the calculation of the noduledoubling time. Computer-aided assessment of the growth of lung nodules should always be performed using the same version of volumetric software and the same segmentation algorithm. © Springer-Verlag 2010.

Snow M.S.,University of Oxford | Howard B.J.,University of Oxford | Evangelisti L.,DellUniversity Bologna | Caminati W.,DellUniversity Bologna
Journal of Physical Chemistry A | Year: 2011

Five different hydrogen-bonded conformers of the dimer of 2-propanol have been characterized by Fourier transform microwave spectroscopy. In all observed species, the proton donor moiety adopts a gauche conformation. While in the gauche monomer a transient chirality takes place, all dimers are classical chiral systems. The Ubbelohde effect has been observed upon OH → OD isotopic substitution and its structural effects - a 5 mÅ reduction of the O - -O distance - have been quantitatively defined. © 2010 American Chemical Society.

Discover hidden collaborations