Search results for "Continuous"
showing 10 items of 899 documents
Fast and compact data acquisition for gas-filled detectors with delay line
2004
This article describes the functionality, implementation and performance of a PCI data acquisition board that can be used in conjunction with gas-filled detectors with delay line readout. The board combines a large on-board 256-MByte histogramming memory with a maximum 10-MHz count rate in continuous operation and integrates the time frame generation, histogram building and buffering functionalities in a single PCI board, resulting in a fast, compact and cost-effective data acquisition solution for the Spanish beamline BM16 at ESRF.
Detector characterization and first coincidence tests of a Compton telescope based on LaBr3 crystals and SiPMs
2011
International audience; A Compton telescope for dose monitoring in hadron therapy consisting of several layers of continuous LaBr3 crystals coupled to silicon photomultiplier (SiPM) arrays is under development within the ENVISION project. In order to test the possibility of employing such detectors for the telescope, a detector head consisting of a continuous 16 mm×18 mm×5 mm LaBr3 crystal coupled to a SiPM array has been assembled and characterized, employing the SPIROC1 ASIC as readout electronics. The best energy resolution obtained at 511 keV is 6.5% FWHM and the timing resolution is 3.1 ns FWHM. A position determination method for continuous crystals is being tested, with promising res…
Magnetic resonance imaging of dissolved hyperpolarized 129Xe using a membrane-based continuous flow system.
2009
Abstract A technique for continuous production of solutions containing hyperpolarized 129Xe is explored for MRI applications. The method is based on hollow fiber membranes which inhibit the formation of foams and bubbles. A systematic analysis of various carrier agents for hyperpolarized 129Xe has been carried out, which are applicable as contrast agents for in vivo MRI. The image quality of different hyperpolarized Xe solutions is compared and MRI results obtained in a clinical as well as in a nonclinical MRI setting are provided. Moreover, we demonstrate the application of 129Xe contrast agents produced with our dissolution method for lung MRI by imaging hyperpolarized 129Xe that has been…
Comparison between adaptive and uniform discontinuous Galerkin simulations in dry 2D bubble experiments
2013
Accepted by the Journal of Computational Physics Adaptive mesh refinement generally aims to increase computational efficiency without compromising the accuracy of the numerical solution. However it is an open question in which regions the spatial resolution can actually be coarsened without affecting the accuracy of the result. This question is investigated for a specific example of dry atmospheric convection, namely the simulation of warm air bubbles. For this purpose a novel numerical model is developed that is tailored towards this specific application. The compressible Euler equations are solved with a Discontinuous Galerkin method. Time integration is done with an IMEXmethod and the dy…
Approximation of plurisubharmonic functions
2015
We extend a result by Fornaaess and Wiegerinck [Ark. Mat. 1989;27:257-272] on plurisubharmonic Mergelyan type approximation to domains with boundaries locally given by graphs of continuous functions.
An asymptotic holomorphic boundary problem on arbitrary open sets in Riemann surfaces
2020
Abstract We show that if U is an arbitrary open subset of a Riemann surface and φ an arbitrary continuous function on the boundary ∂ U , then there exists a holomorphic function φ ˜ on U such that, for every p ∈ ∂ U , φ ˜ ( x ) → φ ( p ) , as x → p outside a set of density 0 at p relative to U . These “solutions to a boundary problem” are not unique. In fact they can be required to have interpolating properties and also to assume all complex values near every boundary point. Our result is new even for the unit disc.
Compliance to ventilatory treatment in a cohort of patients on home CPAP or NIV: analysis by diagnosis, treatment type, and comorbidities
2019
Background: Patients on home continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV) show large variability in compliance to treatment. Aim: To identify predictors of poor compliance, we evaluated compliance to treatment in patients with obstructive sleep apnea (OSA), obesity hypoventilation syndrome (OHS), and OSA-chronic obstructive pulmonary disease (COPD) overlap syndrome. Methods: We analyzed clinical and compliance data provided by a single home care provider, in 602 patients (n=442 OSA, males (M) 308; 38 OHS M=15, and 122 overlap M=111) on home CPAP/NIV in the province of Agrigento, Italy, after one year of treatment. The following variables were considered: age, …
Abstract 4010: Prognostic role of miRNAs in resectable non-small cell lung cancer
2015
Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA BACKGROUND MicroRNAs (miRNA) are a class of small RNAs that regulate gene expression, and are implicated in several diseases including cancer. The aim of this study was to analyze the prognostic implications of deregulated miRNAs identified by NGS in a previous study performed on resectable-NSCLC tumor samples. MATERIAL AND METHODS Fresh-frozen tumor and normal adjacent lung tissue samples (N = 195) were obtained by surgical resection from NSCLC patients and storage in RNAlater® at -80°C until analysis. RNA was isolated biological specimens by Trizol based-methods. 22 deregulated miRNA were analyzed in paired t…
High flow nasal therapy in perioperative medicine: from operating room to general ward
2018
Abstract Background High flow nasal therapy (HFNT) is a technique in which humidified and heated gas is delivered to the airways through the nose via small nasal prongs at flows that are higher than the rates generally applied during conventional oxygen therapy. The delivered high flow rates combine mixtures of air and oxygen and enable different inspired oxygen fractions ranging from 0.21 to 1. HFNT is increasingly used in critically ill adult patients, especially hypoxemic patients in different clinical settings. Main body Noninvasive ventilation delivers positive pressure (end-expiratory and inspiratory pressures or continuous positive airway pressure) via different external interfaces. …
Identification of a Hammerstein model for DC/DC converters operating in CCM
2005
This paper deals with a method for identification of a Hammerstein model of DC-DC converters operating in continuous conduction mode (CCM). This model has the duty cycle and the output voltage as input and output, respectively; it consists of a static nonlinearity and a linear and time-invariant model. The aim of the modeling the system by means of a Hammerstein model is due to its capability of describing the converter in a range of steady-state operating points instead of a desired well defined operating point as occurs for the small-signal models which are the more common mathematical description to approach the study of the converters themselves. The nonlinear characteristic of the Hamm…