Search results for " Ultrasonic"

Towards a full Heusler alloy showing room temperature half-metallicity at the surface

2007

In this article we investigate the surface spin polarization in a 100 nm Co2Cr0.6Fe0.4Al (CCFA) film grown ex situ epitaxially on MgO(100) with a 10 nm Fe buffer layer by means of spin resolved photoemission. We show that a careful in situ preparation of the sample surface leads to values for the room temperature spin polarization up to 45% at the Fermi level. To our knowledge, this is the highest value measured so far at the surface region of a full Heusler alloy at room temperature.

Semiconductor optical waveguide devices modulated by surface acoustic waves

2019

Surface waves on cylindrical solids: numerical and experimental study.

2013

The use of Rayleigh waves enables the solution of several important inspection problems. Propagation of surface waves along straight boundaries has been properly studied but investigations about their propagation on cylindrical surfaces are not sufficient, despite they can be still of interest for NDE applications. It has been proved experimentally that a surface wave pulse suffers a phase shift during its propagation along a cylindrical surface. A numerical approach has been developed to efficiently study these effects for different materials, curvatures and frequencies. This study can help the scientific community to better understand the phenomenon, quite complex and not yet fully explor…

Application of the method: Diagnostic survey of the flooring with majolica tiles in the Mirrors Gallery of Comitini Palace in Palermo

2008

Poster presented at the International Conference and Workshop "Teaching Conservation/Restoration of Architectural Heritage, Goals, Contents and Methods", EAAE-ENHSA, Genova, 18-20 ottobre 2007.

A linear generator for a waveroller power device

2017

In this paper experimental tests on a small scale tubular linear generator to be applied to wave rollers device are presented. A reduced scale of gnerator is presented and experimental results obtained in on test bench are shown. Experimental waveforms of current and voltage are recorded. Simulation results are compared to the experimental ones in order to validate the mathematical models used.

Effect of ultrasound pre-treatment and drying method on specialized metabolites of honeyberry fruits (Lonicera caerulea var. kamtschatica).

2019

Abstract Honeyberries are rich in various nutrients (eg. minerals, and vitamins) and bioactive compounds (eg. polyphenols). The aim of the study was to evaluate the impact of ultrasound (USN) pre-treatment (100% power at 37 kHz) at 40 °C for 3 min and drying techniques (conduction or vacuum) on nutritional composition and bioactive compounds of honeyberry fruits. The evaluation of dried barriers revealed that both USN pre-treatment and drying techniques affected the composition of the final product. The highest vitamin C content (1.067–1.187 mg 100 g−1 DM) was found in fruit samples pre-treated by USN, regardless of the drying technology used. The highest total phenol (2.445 mg GAE 100 g−1 …

Acoustic methods for measuring the porosities of porous materials incorporating dead-end pores

2013

International audience; The acoustic properties of porous materials containing dead-end (DE) pores have been proposed by Dupont et al. [J. Appl. Phys. 110, 094903 (2011)]. In the theoretical description, two physical parameters were defined (the dead-end porosity and the average length of the dead-end pores). With the knowledge of the open porosity (measured with non-acoustic methods), and the measurement of kinematic porosity (also called the Biot porosity in this article), it is possible to deduce the dead-end porosity. Two acoustic methods for measuring the Biot porosity for a wide range of porosities are proposed. These methods are based on acoustic transmission and on the low and high …

A one-dimensional model for dynamic analysis of generally layered magneto-electro-elastic beams

2013

Abstract A new one-dimensional model for the dynamic problem of magneto-electro-elastic generally laminated beams is presented. The electric and magnetic fields are assumed to be quasi-static and a first-order shear beam theory is used. The electro-magnetic problem is first solved in terms of the mechanical variables, then the equations of motion are written leading to the problem governing equations. They involve the same terms of the elastic dynamic problem weighted by effective stiffness coefficients, which take the magneto-electro-mechanical couplings into account. Additional terms, which involve the third spatial derivative of the transverse displacement, also occur as a result of the …

Tomografia Sonica ed Ultrasonica per il supporto all’intervento di restauro della statua del togato di Petrara (I Sec. D.C.)

2008

Nel 2003, a Locri (RC), è stata ritrovata la statua-ritratto in marmo del c.d. “togato di Petrara” (I sec. d.C.), rappresentata in Fig. 1, come si presenta dopo il restauro. Si tratta, probabilmente di una statua onoraria di un magistrato del municipium locrese, alta circa m 2,16 ma spezzata in tre parti: piedi con basetta, testa e figura. Dal marzo al luglio 2008 sono state eseguite le operazioni di restauro del manufatto per ricomporre la statua e porla nuovamente in posizione eretta. Una notevole lesione, infatti, era visibile sul fianco sinistro e sul retro. La causa di tale lesione si individuava subito con la presenza di un grosso perno a sezione quadrata inserito già in antico per il…

Tomographic diagnostics of high-frequency electrodeless lamps in argon–mercury mixtures

2006

Tomographic reconstruction of spatial profiles of the mercury atom density in the excited state 7 3S1 in high-frequency electrodeless lamps (HFELs) has been performed. The measurements of the Hg 546.1 nm line emission intensity have been made for the HFELs in argon–mercury mixture depending on the operation regime with different cold spot temperatures in the range 31–98 °C. The maximum entropy-based algorithm was applied for the reconstruction of local emission coefficients from the integrated intensities. The emission coefficients are directly related to the local values of the mercury atom density in the excited state 7 3S1, the upper state of the 546.1 nm transition. Such an investigatio…