Search results for "Shape"

Coulomb excitation of Rn-222

2022

The nature of quadrupole and octupole collectivity in 222Rn was investigated by determining the electric-quadrupole (E2) and octupole (E3) matrix elements using subbarrier, multistep Coulomb excitation. The radioactive 222Rn beam, accelerated to 4.23 MeV/u, was provided by the HIE-ISOLDE facility at CERN. Data were collected in the Miniball γ-ray spectrometer following the bombardment of two targets, 120Sn and 60Ni. Transition E2 matrix elements within the ground-state and octupole bands were measured up to 10ℏ and the results were consistent with a constant intrinsic electric-quadrupole moment, 518(11)efm2. The values of the intrinsic electric-octupole moment for the 0+→3− and 2+→5− transi…

Sharp estimates and saturation phenomena for a nonlocal eigenvalue problem

2011

Abstract We determine the shape which minimizes, among domains with given measure, the first eigenvalue of a nonlocal operator consisting of a perturbation of the standard Dirichlet Laplacian by an integral of the unknown function. We show that this problem displays a saturation behaviour in that the corresponding value of the minimal eigenvalue increases with the weight affecting the average up to a (finite) critical value of this weight, and then remains constant. This critical point corresponds to a transition between optimal shapes, from one ball as in the Faber–Krahn inequality to two equal balls.

Segmentation Integrating Texture and Shape A Priori Applied to Cardiac MR Images

2017

International audience; Cardiovascular diseases are the first cause of death worldwide. Early and accurate diagnosisof cardiovascular diseases plays an important role in improving life of population afflicted heartdiseases. Delayed Enhencement Magnetic Resonance Imaging (DE-MRI) is a highly valuablebut non-specific imaging technique that is ancillary in the diagnosis of a variety of myocardialdiseases. This papper presents a novel segmentation technique of DE-MRI based on watershedand region growing algorithm with application of myocardium shape.

Double β Decay and the Axial Strength

2019

Quenching of the weak axial strength gA is discussed and relations of this quenching to the nuclear matrix elements of double beta decays are highlighted. An analysis of Gamow-Teller transitions in the mass range A = 62 − 142 is presented and its results are compared with those of many previous works. The enhancement of the axial charge is discussed for first-forbidden pseudoscalar β transitions. Higher-forbidden β transitions are introduced and their role in determining the effective value of gA is examined, in particular from the point of view of the β-decay half-lives and the shapes of electron spectra of forbidden non-unique β transitions. peerReviewed

<title>Restoration of a short-exposure image sequence degraded by atmospheric turbulence</title>

2000

This paper deals with the restoration of the shape of an object observed with a high-resolution infrared imaging device, through atmospheric turbulence. The propagation path is quite long (a few tenth kilometer) and the image is thus disturbed. A sequence of short-exposure images of the interesting object is recorded. We can see that the object shape fluctuates randomly during the sequence, but that its edges remain sharp, thanks to the very short exposure time. A bayesian analysis of the Fourier descriptors associated to the edges shows that the optimal shape is the one corresponding to the mean Fourier descriptors. We thus propose two ways to estimate this shape. The first one consists in…

EFFECT OF FRUIT-SET TIME ON THE QUALITY PERFORMANCE OF ANNONA CHERIMOLA MILL. FRUIT

2019

The aim of this work was to analyze the differences between fruits obtained by different dates of fruit set and identify the proper fruit-set time that allows to obtain the optimum fruit quality in Annona cherimola cv Fino de Jete, planted in Southern Italy. Six fruit-set dates were selected from the first week of June to the second week of July. Fruits were sampled from October to November, when 1500 Growing Degree Days (DD) were accumulated; The DD were calculated using a base temperature of 12 °C. Fruit fresh weight (FW) and skin colour were measured. These parameters were measured also after storage, and in addition, the following parameters were measured: fruit shape (FS), pulp colour,…

Performance Assessment of Posidonia oceanica (L.) Delile Restoration Experiment on Dead matte Twelve Years after Planting—Structural and Functional M…

2021

Following the restoration of natural conditions by reducing human pressures, reforestation is currently considered a possible option to accelerate the recovery of seagrass habitats. Long-term monitoring programs theoretically represent an ideal solution to assess whether a reforestation plan has produced the desired results. Here, we report on the performance of a 20 m2 patch of Posidonia oceanica transplanted on dead matte twelve years after transplantation in the Gulf of Palermo, northwestern Sicily. Photo mosaic performed in the area allowed us to detect 23 transplanted patches of both regular and irregular shape, ranging from 0.1 to 2.7 m2 and an overall surface close to 19 m2. Meadow d…

Shape change during the growth of sharpsnout seabream reared under different conditions in a fish farm of the southern Tyrrhenian Sea

2003

Fullerene-Polymers: Synthesis, Properties and Applications

2009

Written by an outstanding team of experts in the interdisciplinary areas of research, this book is based on a new classification of the different types of fullerene polymers according to their chemical structures. It covers all aspects, from different classes, to their synthesis and applications in material science. Of great interest to polymer and synthetic chemists, but also for material scientists and industrial chemists.

Photoactivity of Shape-Controlled TiO2 in Gas-Solid Regime Under Solar Irradiation

2018

Shape-controlled TiO2 materials have been tested as photocatalysts under both simulated and natural solar irradiation.