Search results for " Opera"

A wavelet operator in solving electromagnetic fields equations in time domain

2010

Exploring the properties of MTO4compounds using high-pressure powder x-ray diffraction

2015

Several ternary oxides with industrial applications, but also interesting for basic research, have been studied recently at room temperature under high-pressure conditions using synchrotron powder x-ray diffraction. In this article, part of these experiments will be summarized. The studied materials include zircon-type vanadates and scheelite-type tungstates as well as other oxides related to them. Several pressure-induced structural phase transitions that take place in these compounds under compression will be here described. In addition, the determination of the crystal structure of the high-pressure phases will be discussed. The reported studies have also allowed the accurate determinati…

Dense Post-Barite-type Polymorph of PbSO4 Anglesite at High Pressures

2019

Synchrotron X-ray diffraction measurements on lead sulfate have been performed up to 67 GPa using He as pressure transmitting medium. Experiments reveal the existence of a reversible pressure-induced phase transition from the initial Pnma barite-type to the P212121 post-barite-type structure at pressures above 27 GPa. This phase transition involves a volume collapse of 2.4% and requires a considerable pressure overshoot (large pressure range with coexistence of phases) to overcome the large kinetic barrier of the transition. DFT calculations confirm the experimental observations and support the hypothesis that post-barite-type phase is the thermodynamically stable high-pressure structure fo…

Investigation of AC Electrical Properties of MXene-PCL Nanocomposites for Application in Small and Medium Power Generation

2021

The paper examined Ti3C2Tx MXene (T—OH, Cl or F), which is prepared by etching a layered ternary carbide Ti3AlC2 (312 MAX-phase) precursor and deposited on a polycaprolactone (PCL) electrospun membrane (MXene-PCL nanocomposite). X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy (SEM) indicates that the obtained material is pure Ti3C2 MXene. SEM of the PCL-MXene composite demonstrate random Ti3C2 distribution over the nanoporous membrane. Results of capacitance, inductance, and phase shift angle studies of the MXene-PCL nanocomposite are presented. It was found that the frequency dependence of the capacitance exhibited a clear sharp minima in the frequency range of 50 Hz to o…

ChemInform Abstract: Exploring the Properties of MTO4Compounds Using High-Pressure Powder X-Ray Diffraction

2015

Several ternary oxides with industrial applications, but also interesting for basic research, have been studied recently at room temperature under high-pressure conditions using synchrotron powder x-ray diffraction. In this article, part of these experiments will be summarized. The studied materials include zircon-type vanadates and scheelite-type tungstates as well as other oxides related to them. Several pressure-induced structural phase transitions that take place in these compounds under compression will be here described. In addition, the determination of the crystal structure of the high-pressure phases will be discussed. The reported studies have also allowed the accurate determinati…

Progetto Digital Twins: un sopralluogo analogico e digitale a Gratosoglio. Lo sguardo da Palermo

2022

The description of an ongoing project has the value of establishing some points of reflection useful to adjust the shot for the next phases of an experiment. In this paper, we are describing an ongoing project between Politecnico di Milano and Università degli Studi di Palermo. The feature on which this experimentation focuses is the analog/ digital survey, which tries to generate a “satellite” point of view, (a group of people physically in the analyzed area), and a “remote” one. The paper, firstly underlines the importance of surveys in urban planning, secondly displays the techniques, operators and equipment which are needed and it concludes with some considerations.

Categorical Modeling Method of Intelligent WorkFlow

2018

A category as well as a model is a mixture of graphical information and algebraic operations. Therefore, category language seems to be the most general to describe the models. It can provide us with the features that must characterize both the DSL language and the Modeling Method concept.

A Weitzenböck formula for the damped Ornstein–Uhlenbeck operator in adapted differential geometry

2001

Abstract On the Riemannian path space we consider the Ornstein–Uhlenbeck operator associated to the Dirichlet form E (f,g)=E〈 ∇ f, ∇ g〉 H , where ∇ is the damped gradient and 〈·,·〉 H the scalar product of the Cameron–Martin space H . We prove a corresponding Weitzenbock formula restricted to adapted vector fileds: the Ricci-tensor is shown to be equal to the identity.

(p, 2)-Equations with a Crossing Nonlinearity and Concave Terms

2018

We consider a parametric Dirichlet problem driven by the sum of a p-Laplacian ($$p>2$$) and a Laplacian (a (p, 2)-equation). The reaction consists of an asymmetric $$(p-1)$$-linear term which is resonant as $$x \rightarrow - \infty $$, plus a concave term. However, in this case the concave term enters with a negative sign. Using variational tools together with suitable truncation techniques and Morse theory (critical groups), we show that when the parameter is small the problem has at least three nontrivial smooth solutions.

Elliptic equations involving the $1$-Laplacian and a subcritical source term

2017

In this paper we deal with a Dirichlet problem for an elliptic equation involving the $1$-Laplacian operator and a source term. We prove that, when the growth of the source is subcritical, there exist two bounded nontrivial solutions to our problem. Moreover, a Pohozaev type identity is proved, which holds even when the growth is supercritical. We also show explicit examples of our results.