Search results for " Emission"

Ultraprecise Rydberg atomic localization using optical vortices

2020

We propose a robust localization of the highly-excited Rydberg atoms, interacting with doughnut-shaped optical vortices. Compared with the earlier standing-wave (SW)-based localization methods, a vortex beam can provide an ultrahigh-precision two-dimensional localization solely in the zero-intensity center, within a confined excitation region down to the nanometer scale. We show that the presence of the Rydberg-Rydberg interaction permits counter-intuitively much stronger confinement towards a high spatial resolution when it is partially compensated by a suitable detuning. In addition, applying an auxiliary SW modulation to the two-photon detuning allows a three-dimensional confinement of R…

Coherent Control of Stimulated Emission inside one dimensional Photonic Crystals:Strong Coupling regime

2006

The present paper discusses the stimulated emission, in strong coupling regime, of an atom embedded inside a one dimensional (1D) Photonic Band Gap (PBG) cavity which is pumped by two counter-propagating laser beams. Quantum electrodynamics is applied to model the atom-field interaction, by considering the atom as a two level system, the e.m. field as a superposition of normal modes, the coupling in dipole approximation, and the equations of motion in Wigner-Weisskopf and rotating wave approximations. In addition, the Quasi Normal Mode (QNM) approach for an open cavity is adopted, interpreting the local density of states (LDOS) as the local density of probability to excite one QNM of the ca…

Destructuration of typical Sicilian calcarenites

2010

The paper discusses some interesting features of Sicilian fine grain calcarenites. Uniaxial, triaxial, oedometer and isotropic compression tests were undertaken on intact specimens of two types of calcarenite in order to investigate their mechanical characteristics. It was found that the strength and deformability is significantly influenced by the structure (fabric and bonding) and by the destructuration processes. A better understanding of fracture development behavior is gained through a combination of acoustic emission and photographic monitoring on non-homogeneous samples with natural pre-existing heterogeneities due to cementation or to density. The results show that the destructurati…

Measurement of the heaviest Beta-delayed 2-neutron emitter: 136Sb

2017

The Beta-delayed neutron emission probability, Pn , of very exotic nuclei is crucial for the understanding of nuclear structure properties of many isotopes and astrophysical processes such as the rapid neutron capture process (r-process). In addition Beta-delayed neutrons are important in a nuclear power reactor operated in a prompt sub-critical, delayed critical condition, as they contribute to the decay heat inducing fission reactions after a shut down. The study of neutron-rich isotopes and the measurement of Beta-delayed one-neutron emitters (Beta1n) is possible thanks to the Rare Isotope Beam (RIB) facilities, where radioactive beams allow the production of exotic nuclei of interest, w…

The Effect of Combustion Dynamics on the Formation of Pollutant Emissions by Co-Firing the Wood Biomass with Gaseous Fuel

2008

On the Use of a Hydrogen-Fueled Engine in a Hybrid Electric Vehicle

2022

Featured Application: The specific application of this research could be the implementation of a hydrogen-fueled engine in a hybrid electric vehicle in order to improve the engine efficiency and to eliminate its exhaust emissions. Hybrid electric vehicles are currently one of the most effective ways to increase the efficiency and reduce the pollutant emissions of internal combustion engines. Green hydrogen, produced with renewable energies, is an excellent alternative to fossil fuels in order to drastically reduce engine pollutant emissions. In this work, the author proposes the implementation of a hydrogen-fueled engine in a hybrid vehicle; the investigated hybrid powertrain is the power-s…

Artificial Intelligence Applications on Restaging [18F]FDG PET/CT in Metastatic Colorectal Cancer: A Preliminary Report of Morpho-Functional Radiomic…

2022

Featured Application Based on results defined in this study, new investigations might propose morpho-functional-based radiomics algorithms for risk stratification with possible impact on treatment management in colorectal cancer. The aim of this study was to investigate the application of [F-18]FDG PET/CT images-based textural features analysis to propose radiomics models able to early predict disease progression (PD) and survival outcome in metastatic colorectal cancer (MCC) patients after first adjuvant therapy. For this purpose, 52 MCC patients who underwent [F-18]FDGPET/CT during the disease restaging process after the first adjuvant therapy were analyzed. Follow-up data were recorded f…

[ 18 F]Fluoroethylflumazenil: a novel tracer for PET imaging of human benzodiazepine receptors

2001

5-(2'-[18F]Fluoroethyl)flumazenil ([18F]FEF) is a fluorine-18 labelled positron emission tomography (PET) tracer for central benzodiazepine receptors. Compared with the established [11C]flumazenil, it has the advantage of the longer half-life of the fluorine-18 label. After optimisation of its synthesis and determination of its in vitro receptor affinities, we performed first PET studies in humans. PET studies in seven healthy human volunteers were performed on a Siemens ECAT EXACT whole-body scanner after injection of 100-280 MBq [L8F]FEF. In two subjects, a second PET scan was conducted after pretreatment with unlabelled flumazenil (1 mg or 2.5 mg i.v., 3 min before tracer injection). A t…

Synthesis and preliminary evaluation of (R,R)(S,S) 5-(2-(2-[4-(2-[18F]fluoroethoxy)phenyl]-1-methylethylamino)-1-hydroxyethyl)-benzene-1,3-diol ([18F…

2003

The 18 F-labeled b2-adrenergic receptor ligand (R,R)(S,S) 5-(2-(2-(4-(2-( 18 F)fluoroethoxy)phenyl)-1-methylethylamino)-1- hydroxyethyl)-benzene-1,3-diol, a derivative of the original highly selective racemic fenoterol, was synthesized in an overall radio- chemical yield of 20% after 65 min with a radiochemical purity higher than 98%. The specific activity was in the range of 50-60 GBq/mmol. In vitro testing of the non-radioactive fluorinated fenoterol derivative with isolated guinea pig trachea was conducted to obtain an IC50 value of 60 nM. Preliminary ex vivo organ distribution and in vivo experiments with positron emission tomography (PET) on guinea pigs were performed to study the biod…

Improved automated synthesis of [18F]fluoroethylcholine as a radiotracer for cancer imaging.

2007

[(18)F]Fluoroethylcholine has been recently introduced as a promising (18)F-labelled analogue of [(11)C]choline which had been previously described as a tracer for metabolic cancer imaging with positron emission tomography (PET). Due to the practical advantages of using the longer-lived radioisotope (18)F (t(1/2)=110 min), offering the opportunity of a more widespread clinical application, we established a reliable, fully automated synthesis for its production using a modified, commercially available module. [(18)F]Fluoroethylcholine was prepared from N,N-dimethylaminoethanol by iodide catalyzed alkylation with 1-[(18)F]fluoro-2-tosylethane as alkylating agent, resulting in a total radioche…