Search results for " method"
showing 10 items of 10455 documents
Reliability of PEA Measurement in Presence of an Air Void Defect
2020
This paper deals with the reliability of the Pulsed Electro-Acoustic (PEA) technique in the case of a specimen containing an air layer. The first approach to this study has been proposed by the authors in previously published works. In these papers, the mathematical description, the PEA cell simulation model, and some experimental tests have been reported. In this work, a more accurate description of the acoustic wave behavior within the PEA cell and specimen with and without an air layer is given. Moreover, the comparison between simulation and experimental tests for both cases (specimen with and without air layer) allowed the validation of the previously developed PEA cell simulation mode…
Interpretation of PEA Output Signal in a Multilayer Specimen
2018
The aim of the present work is to evaluate the acoustic waves behavior within the Pulsed Electro-Acoustic (PEA) cell, in case of a multilayer specimen, in order to avoid misinterpretation of the output signal. Due to the reflection phenomenon of the acoustic waves travelling within the PEA cell, the output signal could be distorted. Because this aspect, for a given PEA cell with certain ground electrode and absorber thicknesses, depends on the sound velocity and thickness of the specimen under test, the latter must be carefully sized. For this aim, some useful relationships, that must be taken into account are given and described. In particular, a three layers sample simulating an air void …
Impact of a minimally processing route for the production of infant formulas on the organoleptic properties
2022
Many new-borns are fed with substitutes of breast milk. These products undergo several heat treatments, necessary to insure their microbiologic safety but probably modifying their organo-leptic properties. High temperature can damage milk proteins and form Maillard reaction prod-ucts with lactose. Microfiltration – to replace the heat treatments for a milk debacterization – combined with a soft spray-drying is currently an alternative little exploited to produce infant formulas (IFs) although microbiologically safe. The aim of this study was to determine the im-pact of such processing route on the organoleptic properties of the IFs. Three experimental IFs were manufactured at a semi-industr…
Effects of Dissolved Complexation on REE Fate During Interactions between Volcanic Ash and Coexisting Fluids
2013
AbstractThis work analyzes REE behavior during the delivery of volcanic ash into a marine system and highlights the effects induced by dissolved carbonate and humate complexes on REE release. Kinetic experiments were carried out during a 6-month period using a batch method approach. Results show that the highest degree of REE leaching occurs during the early stage. Altered phases that crystallize induce REE sorption and dissolved complexation towards surface complexation, concurrent processes that are enhanced by Y/Ho, La/Yb, and Ce/Ce* changes, whereas dissolved humates and carbonates influence the dissolution rate of ash and the dissolved REE behavior.
In situ Volcano Monitoring: Present and Future
2015
During the last couple of decades, volcanology has evolved significantly, allowing for an improved understanding of volcanic processes preceding, accompanying and following eruptive events. Key elements to these achievements are the huge amounts of high quality data being collected by networks of increasingly sensitive instruments deployed at active volcanoes. The diffusion of continuous, precise measurements of: (1) wide-band ground displacement; (2) flux and chemistry of volatile emissions; and (3) the spatio-temporal variations of potential fields (e.g., gravity) now permit imaging the mechanism that controls mass transfer underneath volcanoes to an unprecedented level of detail. Joined …
An adaptive method for Volterra–Fredholm integral equations on the half line
2009
AbstractIn this paper we develop a direct quadrature method for solving Volterra–Fredholm integral equations on an unbounded spatial domain. These problems, when related to some important physical and biological phenomena, are characterized by kernels that present variable peaks along space. The method we propose is adaptive in the sense that the number of spatial nodes of the quadrature formula varies with the position of the peaks. The convergence of the method is studied and its performances are illustrated by means of a few significative examples. The parallel algorithm which implements the method and its performances are described.
Constraining the spin-dependent WIMP-nucleon cross sections with XENON1T
2019
We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3 × 10−42 cm2 at 30 GeV/c2 and 90% confidence level. The results are compared with those from collider searches and used to exclude new paramet…
Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector
2017
International audience; We report on weakly interacting massive particles (WIMPs) search results in the XENON100 detector using a nonrelativistic effective field theory approach. The data from science run II (34 kg×224.6 live days) were reanalyzed, with an increased recoil energy interval compared to previous analyses, ranging from (6.6–240) keVnr. The data are found to be compatible with the background-only hypothesis. We present 90% confidence level exclusion limits on the coupling constants of WIMP-nucleon effective operators using a binned profile likelihood method. We also consider the case of inelastic WIMP scattering, where incident WIMPs may up-scatter to a higher mass state, and …
Projected WIMP sensitivity of the XENONnT dark matter experiment
2020
XENONnT is a dark matter direct detection experiment, utilizing 5.9 t of instrumented liquid xenon, located at the INFN Laboratori Nazionali del Gran Sasso. In this work, we predict the experimental background and project the sensitivity of XENONnT to the detection of weakly interacting massive particles (WIMPs). The expected average differential background rate in the energy region of interest, corresponding to (1, 13) keV and (4, 50) keV for electronic and nuclear recoils, amounts to 12.3 ± 0.6 (keV t y)-1 and (2.2± 0.5)× 10−3 (keV t y)-1, respectively, in a 4 t fiducial mass. We compute unified confidence intervals using the profile construction method, in order to ensure proper coverage…
Agent assisted interactive algorithm for computationally demanding multiobjective optimization problems
2015
Abstract We generalize the applicability of interactive methods for solving computationally demanding, that is, time-consuming, multiobjective optimization problems. For this purpose we propose a new agent assisted interactive algorithm. It employs a computationally inexpensive surrogate problem and four different agents that intelligently update the surrogate based on the preferences specified by a decision maker. In this way, we decrease the waiting times imposed on the decision maker during the interactive solution process and at the same time decrease the amount of preference information expected from the decision maker. The agent assisted algorithm is not specific to any interactive me…