Search results for "PLASMA"
showing 10 items of 4043 documents
Noise-enhanced propagation in a dissipative chain of triggers
2002
International audience; We study the influence of spatiotemporal noise on the propagation of square waves in an electrical dissipative chain of triggers. By numerical simulation, we show that noise plays an active role in improving signal transmission. Using the Signal to Noise Ratio at each cell, we estimate the propagation length. It appears that there is an optimum amount of noise that maximizes this length. This specific case of stochastic resonance shows that noise enhances propagation.
Noise Induced Phenomena in the Dynamics of Two Competing Species
2015
Noise through its interaction with the nonlinearity of the living systems can give rise to counter-intuitive phenomena. In this paper we shortly review noise induced effects in different ecosystems, in which two populations compete for the same resources. We also present new results on spatial patterns of two populations, while modeling real distributions of anchovies and sardines. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. We find noise induced phenomena such as quasi-deterministic oscillations, stochastic resonance, noise …
WENO schemes applied to the quasi-relativistic Vlasov-Maxwell model for laser-plasma interaction
2014
Abstract In this paper we focus on WENO-based methods for the simulation of the 1D Quasi-Relativistic Vlasov–Maxwell (QRVM) model used to describe how a laser wave interacts with and heats a plasma by penetrating into it. We propose several non-oscillatory methods based on either Runge–Kutta (explicit) or Time-Splitting (implicit) time discretizations. We then show preliminary numerical experiments.
The Sensor Kinase DctS Forms a Tripartite Sensor Unit with DctB and DctA for Sensing C4-Dicarboxylates in Bacillus subtilis
2013
The DctSR two-component system of Bacillus subtilis controls the expression of the aerobic C4-dicarboxylate transporter DctA. Deletion of DctA leads to an increased dctA expression. The inactivation of DctB, an extracellular binding protein, is known to inhibit the expression of dctA. Here, interaction between the sensor kinase DctS and the transporter DctA as well as the binding protein DctB was demonstrated in vivo using streptavidin (Strep) or His protein interaction experiments (mSPINE or mHPINE), and the data suggest that DctA and DctB act as cosensors for DctS. The interaction between DctS and DctB was also confirmed by the bacterial two-hybrid system (BACTH). In contrast, no indicati…
IMPROVED PRODUCTION OF THE ANTIBIOTIC ACTINORHODIN IN STREPTOMYCES COELICOLOR IMMOBILIZED-MYCELIAL CELL CULTIVATIONS
2017
Objectives i) Evaluation of ACT production in Streptomyces coelicolor M145 mycelial cells immobilized on polycaprolactone (PCL) and polylactic acid (PLA) nanofiber membranes, modified or not by an O2- plasma treatment. ii) Identification of gene products associated with the improvement of ACT production.
Geography versus topology in the European Ownership Network
2011
In this paper, we investigate the network of ownership relationships among European firms and its embedding in the geographical space. We carry out a detailed analysis of geographical distances between pairs of nodes, connected by edges or by shortest paths of varying length. In particular, we study the relation between geographical distance and network distance in comparison with a random spatial network model. While the distribution of geographical distance can be fairly well reproduced, important deviations appear in the network distance and in the size of the largest strongly connected component. Our results show that geographical factors allow us to capture several features of the netw…
Partial least squares modelization of energy dispersive X-ray fluorescence.
2019
As a proof of concept, a green methodology has been developed for the energy dispersive X-ray fluorescence (ED-XRF) determination of calcium, potassium, iron, magnesium, aluminum, chromium, strontium, phosphorus and nickel in the peel of untreated kaki fruit (Diospyros kaki. L) samples. ED-XRF spectra of fifty-six kakis purchased in the local area of LLombay (Valencia) were obtained directly from samples without any previous treatment and without sample damage just after cleaning the fruit with distilled water. Inductively Couple Plasma Optical Emission Spectrometry (ICP-OES) was used as a reference method to determine the mineral elements after microwave assisted acid digestion. XRF spectr…
Study of low-pressure suspension plasma spray nanostructured coating : structural characteristics and application in solid oxide fuel cell
2021
Suspension plasma spraying (SPS) has attracted more and more attention in terms of the preparation of nanostructured / sub-microstructured ceramic coatings. However, conventional SPS techniques are conducted under atmospheric pressure, which inevitably causes some disadvantages. Recently, a novel suspension spraying technology – low-pressure suspension plasma spraying (LPSPS) – was proposed, in which the sus-pension spraying process is conducted under low environmental pressure. Benefit from the significant impact of low pressure on the coating deposition, LPSPS is expected to improve the disadvantage of SPS as well as to obtain distinct coating structures not achievable in conventional SPS…
Numerical assessment of the thermomechanical behaviour of the DEMO Water-Cooled Lithium Lead inboard blanket equatorial module
2018
Abstract Within the framework of EUROfusion R&D activity, a research campaign has been carried out at the University of Palermo, in close cooperation with ENEA labs, in order to assess the thermo-mechanical performances of the DEMO Water-Cooled Lithium Lead (WCLL) inboard blanket equatorial module, whether properly integrated within its whole inboard segment. In particular, a detailed 3D model of this segment, including all the other modules, the back-supporting structure and the attachment system, has been considered in order to realistically simulate the boundary conditions affecting the equatorial module behaviour. The study has been focused on the investigation of the module thermo-mech…
Thermomechanical analysis supporting the preliminary engineering design of DONES target assembly
2018
Abstract The design of the Demo Oriented NEutron Source (DONES) is the main objective of the Work Package Early Neutron Source (WPENS) of EUROfusion Power Plant Physics and Technology (PPPT) programme. DONES is an IFMIF-based neutron source with the goal of testing and qualifying candidate materials to be used in DEMO and future fusion power plants. In the framework of these activities, a research campaign has been carried out at the University of Palermo, in close cooperation with ENEA labs, in order to assess the thermomechanical performances of the DONES target system, endowed with an integrated Target Assembly (TA) when it undergoes the thermomechanical loads typical of its nominal oper…