Search results for " abl"

showing 10 items of 296 documents

Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
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Referenceless thermometry using radial basis function interpolation

2014

The Proton Resonance Frequency (PRF) shift provide a method for temperature change measurements during thermotherapy. Conventional PRF thermometry works subtracting one or multiple baseline images. The method leads to artifacts caused by tissue motion and frequency drift. Various works estimating the background phase from each acquired image phase are present in literature. These algorithms are called “referenceless” because they don’t require any subtraction of baseline images for calculating temperature increment. Conventional referenceless methods estimate baseline image by fitting the background phase outside the heated region through a polynomial approach. In this work a background pha…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniMaterials sciencebusiness.industryRadial basis function interpolationThermometry ultrasound thermal ablation referenceless methods RBF interpolation MRgFUSComputer visionArtificial intelligencebusinessComputational physics2014 World Symposium on Computer Applications & Research (WSCAR)
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L'elemento acqua nella tradizione islamica

2014

Questo intervento tocca l'argomento elemento acqua così come viene mostrato dalle principali fonti della tradizione islamica: il Corano e la sunna del profeta Muhammad. Dall'acqua passa l'abluzione, sia quella denominata maggiore sia la minore, anche se bisogna considerare che ogni vera purità passa dalla purificazione del cuore. Anche la Sunna cita ripetutamente l'acqua nelle narrazioni relative ad episodi della vita di Muhammad e nei suoi detti. Si constata anche come l'acqua sia oggetto di avvenimenti prodigiosi, mentre nello stesso tempo, varie raccomandazioni ed avvertimenti ruotano nel suo utilizzo.

Settore L-OR/12 - Lingua E Letteratura ArabaCorano Sunna Zamzam abluzione paradiso purificazione abluzioni
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Rappresentazioni e territorio nelle dinamiche del turismo: il caso della Lonely Planet Sicily

2018

L’attuale dibattito sul riordino territoriale del Paese rende nuovamente centrale il concetto di territorio che, da sempre, in una prospettiva geografica pone problemi definitori. Esso può essere, infatti, oggetto di produzioni simboliche e (ri)semantizzazioni in grado di ridefinirlo e di creare specifiche modalità di interazione. A questo proposito, il presente lavoro intende proporre una riflessione su alcune dinamiche di produzione e riproduzione simbolica che interessano il concetto di territorio nel turismo, ambito in cui si può osservare una relazione diretta tra rappresentazione del territorio (intesa anche come narrazione) e possibilità d’azione. In particolare, attraverso il caso s…

Settore M-GGR/02 - Geografia Economico-PoliticaThe current debate about the Italian territorial reorganization makes again fundamental the concept of «territory». This paper aims to reflect on some important dynamics that concern the idea of territory. More in particular I explore in which form it can be (re)semantised through some tourism representations and narrations able to create specific ways of interaction. By taking into account the case study of the Lonely Planet 2017 digital tourist guidebook dedicated to Sicily that splits (and reorganizes) the island in smaller «regions» it is possible to reflect on a complex space dynamic able to redefine the same idea of territory. Indeed the tourist guidebook uses both texts and geographical maps to propose an anthology of homogeneous and coherent destinations to make the Otherness more accessible for the readers. This process demonstrates how symbolic (re)productions of a territory can give rise to specific constructions of places creating different concepts of region and therefore performative spaces and opportunities of «agency». In other terms the (re)definition of the Sicilian territory proposed by the guide invites tourists to consider a new (narrated) geography invites and invites to interact with it thinking as visitors. From a geographical and cultural point of view reflection on these dynamics allows us to consider some (re)definitions of space in relation to forms of textualization (even on the maps). An imaginary but performative geography that attributes to the concept of territory epistemological and gnoseological possibilities.Settore M-GGR/01 - Geografia
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[Role of loco-regional treatments for patients with breast cancer liver metastases].

2009

Settore MED/06 - Oncologia Medicaliver metastases from breast cancerhepatic resectionloco-regional treatment radio-frequency ablation
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Chirurgia trans-cranica mediante ultrasuoni focalizzati ad alta intensità su guida RM: esperienza preliminare a 1,5T

2015

Da qualche anno la chirurgia mediante ultrasuoni focalizzati ad alta intensità guidati da Risonanza Magnetica (Magnetic Resonance guided Focused Ultrasound Surgery, MRgFUS) si sta diffondendo anche in Italia per la palliazione del dolore da metastasi ossee, per il trattamento di tumori ossei primitivi (benigni e non), dei fibromi e dell’adenomiosi uterina; sono già stati inoltre pubblicati i risultati preliminari del trattamento di alcuni tumori epatici, pancreatici, prostatici e della mammella mediante MRgFUS. Questa innovativa tecnica prevede l’utilizzo di un’apparecchiatura di Risonanza Magnetica per il monitoraggio della procedura e sfrutta le caratteristiche fisico- meccaniche degli …

Settore MED/27 - NeurochirurgiaBrain High-Intensity Focused Ultrasound ablation Interventional Magnetic Resonance Imaging Minimally Invasive Surgical Procedures Stereotactic TechniquesSettore MED/37 - Neuroradiologia
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Self-limiting and complete oxidation of silicon nanostructures produced by laser ablation in water

2016

Oxidized Silicon nanomaterials produced by 1064 nm pulsed laser ablation in deionized water are investigated. High-resolution transmission electron microscopy coupled with energy dispersive X-ray spectroscopy allows to characterize the structural and chemical properties at a sub-nanometric scale. This analysis clarifies that laser ablation induces both self-limiting and complete oxidation processes which produce polycrystalline Si surrounded by a layer of SiO2 and amorphous fully oxidized SiO2, respectively. These nanostructures exhibit a composite luminescence spectrum which is investigated by time-resolved spectroscopy with a tunable laser excitation. The origin of the observed luminescen…

Silicon nanocrystal Silica nanoparticles laser ablation Time resolved phtoluminescence High resolution transmission electron microscopy Silicon Oxidation Quantum Confinment DefectsMaterials scienceLaser ablationPhotoluminescenceSiliconSettore FIS/01 - Fisica SperimentaleAnalytical chemistryGeneral Physics and Astronomychemistry.chemical_element02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesAmorphous solidNanomaterialschemistry0210 nano-technologyLuminescenceSpectroscopyTunable laser
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Laser-Ablation-Induced Synthesis of SiO2-Capped Noble Metal Nanoparticles in a Single Step

2010

Here we describe a simple, powerful technique based on the laser ablation of a target immersed in a water solution of a metal salt. With this method, nanoparticles of different metals and alloys can be processed very quickly. Both the target and the salt solution can be chosen to produce metal nanoparticles of different sizes, surface-oxidized nanoparticles (silica-silver, for example), or even more complex structures to be defined by the researcher on one or more steps because the technique combines the advantages of both physical and chemical methods. We have applied this technique to the fabrication of inert silica-metal (silver, gold, and silver-gold) nanoparticles with a strong surface…

SilverSurface PropertiesSilicon dioxideMetal NanoparticlesMineralogyNanoparticleNanotechnologyengineering.materialLaser ablation synthesis in solutionColloidchemistry.chemical_compoundElectrochemistryGeneral Materials ScienceParticle SizeSurface plasmon resonanceSpectroscopyLaser ablationChemistryLasersSurface plasmonSurfaces and InterfacesSilicon DioxideCondensed Matter PhysicsengineeringNoble metalGoldLangmuir
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The usefulness of Sonovue-enhanced pulse-inversion US to assess hepatocellular carcinoma response after percutaneous radiofrequency thermal ablation …

2006

Sonovue hepatocellular carcinoma percutaneous radiofrequency thermal ablation therapy
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Multimodal approaches to the treatment of hepatocellular carcinoma.

2008

The prevalence of hepatocellular carcinoma in Europe and the US is increasing and is currently the leading cause of death in patients with cirrhosis. Surveillance programs for patients with cirrhosis aim to detect tumors at an early stage, when the greatest therapeutic benefits can be achieved. Curative treatments for early-stage tumors include liver transplantation, resection and percutaneous ablation. Transarterial chemoembolization (TACE) and sorafenib can improve survival for patients with intermediate and advanced tumors, respectively. In clinical practice, combination therapies are often used, despite limited evidence to support this approach from randomized controlled trials. Combina…

SorafenibNiacinamidemedicine.medical_specialtyCarcinoma HepatocellularCombination therapyWaiting ListsRadiofrequency ablationPyridinesmedicine.medical_treatmentSalvage therapyAntineoplastic AgentsLiver transplantationlaw.inventionInjectionslawPreoperative CaremedicineCombined Modality TherapyHumansChemoembolization TherapeuticSalvage TherapyHepatologyEthanolbusiness.industryepatocarcinoma cirrosi HBV HCVPhenylurea CompoundsBenzenesulfonatesLiver NeoplasmsGastroenterologySorafenibmedicine.diseaseCombined Modality TherapyEmbolization TherapeuticSurgeryLiver TransplantationHepatocellular carcinomaCatheter AblationRadiotherapy AdjuvantRadiologyPercutaneous ethanol injectionbusinessmedicine.drugNature clinical practice. Gastroenterologyhepatology
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