165 research outputs found
Modeling ITNs Usage: Optimal Promotion Programs Versus Pure Voluntary Adoptions
We consider a mosquito-borne epidemic model, where the adoption by individuals of insecticide–treated bed–nets (ITNs) is taken into account. Motivated by the well documented strong influence of behavioral factors in ITNs usage, we propose a mathematical approach based on the idea of information–dependent epidemic models. We consider the feedback produced by the actions taken by individuals as a consequence of: (i) the information available on the status of the disease in the community where they liv
Stability and bifurcation in plant-pathogens interactions
We consider a plant–pathogen interaction model and perform a bifurcation analysis at the threshold where the pathogen-free equilibrium loses its hyperbolicity. We show that a stimulatory–inhibitory host response to infection load may be responsible for the occurrence of multiple steady states via backward bifurcations. We also find sufficient conditions for the global stability of the pathogen-present equilibrium in case of null or linear inhibitory host response. The results are discussed in the framework of the recent literature on the subject
Oscillation thresholds via the novel MBR method with application to oncolytic virotherapy
Oncolytic virotherapy is a therapy for the treatment of malignant tumours. In some undesirable cases, the injection of viral particles can lead to stationary oscillations, thus preventing the full destruction of the tumour mass. We investigate the oscillation thresholds in a model for the dynamics of a tumour under treatment with an oncolytic virus. To this aim, we employ the minimum bifurcation roots (MBR) method, which is a novel approach to determine the existence and location of Hopf bifurcations. The application to oncolytic virotherapy confirms how this approach may be more manageable than classical methods based on the Routh–Hurwitz criterion. In particular, the MBR method allows to explicitly identify a range of values in which the oscillation thresholds fall
RF Design of the X-band Linac for the EuPRAXIA@SPARC_LAB Project
We illustrate the RF design of the X-band linac for the upgrade of the SPARC_LAB facility at INFN-LNF (EuPRAXIA@SPARC_LAB). The structures are travelling wave (TW) cavities, working on the 2Ď€/3 mode, fed by klystrons with pulse compressor systems. The tapering of the cells along the structure and the cell profiles have been optimized to maximize the effective shunt impedance keeping under control the maximum value of the modified Poynting vector, while the couplers have been designed to have a symmetric feeding and a reduced pulsed heating. In the paper we also present the RF power distribution layout of the accelerating module and a preliminary mechanical design
Measurement of the thermal expansion coefficient of an Al-Mg alloy at ultra-low temperatures
We describe a result coming from an experiment based on an Al-Mg alloy (~ 5%
Mg) suspended bar hit by an electron beam and operated above and below the
termperature of transition from superconducting to normal state of the
material. The amplitude of the bar first longitudinal mode of oscillation,
excited by the beam interacting with the bulk, and the energy deposited by the
beam in the bar are the quantities measured by the experiment. These
quantities, inserted in the equations describing the mechanism of the mode
excitation and complemented by an independent measurement of the specific heat,
allow us to determine the linear expansion coefficient of the material.Comment: 13 pages, 4 figure
A Novel Particle/Photon Detector Based on a Superconducting Proximity Array of Nanodots
The current frontiers in the investigation of high-energy particles demand for new detection methods. Higher sensitivity to low-energy deposition, high-energy resolution to identify events and improve the background rejection, and large detector masses have to be developed to detect even an individual particle that weakly interacts with ordinary matter. Here, we will describe the concept and the layout of a novel superconducting proximity array which show dynamic vortex Mott insulator to metal transitions, as an ultra-sensitive compact radiation-particle detector
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