Composition,Enthalpy, and Vaporization Temperature Calculation of Ag‐SiO<Subscript>2</Subscript> Plasmas with Air in the Temperature Range from 1000 to 6000 K and for Pressure Included between 1 and 50 bars

With the Gibbs free energy minimization method, the molar fraction of chemical species are determined in temperature range included between 1000 and 6000 K for several proportions of air, silver and silica and for pressures included between 1 and 50 bars. The enthalpy and the vaporization temperature of liquid silver and liquid silica are studied. The key role of pressure on composition, enthalpy and the vaporization temperature is shown. The electrical neutrality is study, and the importance of ionized gaseous silver at low temperature is shown even for low amount of silver. The increase of electronegative ions (Ag^– and O^–) with pressure is shown. The vapor pressures fitting coefficients of Ag and SiO₂ are given.     

Exclusive deuteron electrodisintegration at high neutron recoil momentum

We have determined the ²H(e, e′p)n cross section for neutron recoil momenta between 295 and 500 MeV/c. In this region the ³D₁ state contribution is predominant in the deuteron wave function. The high excitation energy (E_cm^np = 179 MeV) and the small momentum transferred (|;q_cm|;² = 1.66 fm^?) emphasize the influence of isobar configurations (IC). Experimental data are compared with calculations including isobar contributions, mesonic exchange currents and final state interactions.     

Mössbauer spectroscopy,dispersion and catalysis

A first part presents and discuss the peculiarities of Mössbauer parameters arising from particle sizes smaller than some tens of nanometers, linewidth, isomer shift, quadrupole interaction, magnetic behaviour,f-factor value and anisotropy. In a second part examples are detailed where catalysts powders during reaction underwent changes in particles sizes, which could be studied by Mössbauer spectroscopy: dispersion increase resulting from iron carburization in Fischer-Fropsch synthesis, changes in particle sizes of iron- or tin-based catalysts used for coal hydroliquefaction.     

NGR study of IrSn4 and Ir3Sn7 intermetallic compounds in external magnetic fields

An interpretation for spectra of IrSn₄ and Ir₃Sn₇ obtained in external magnetic fields is proposed. The trigonal IrSn₄ exhibits asymmetric spectrum without external magnetic field. By application of magnetic field a moderate asymmetry is retained in the split spectra. This asymmetry can be assigned to tin site(s) for which the quadrupole splitting is close to 1.0 mm/s. For the cubic Ir₃Sn₇ no asymmetry is detected, application of the external magnetic field results in the expected splittings.     

Polarization spectroscopy of ICl: The D′, a and a′ states

Three previously-unanalyzed states of ICl are reported, an ion-pair state D′(Ω =2) which converges to the limit I⁺(P₂+ Cl^-(S_o), and two shallow states a(Ω = 1) and a′(Ω = 0⁺) both of which converge to the ground states of separated atoms I(P_{$\text{3}\text{2}$}) + Cl(P_{$\text{3}\text{2}$}). The a(0⁺) state is responsible for the well-known interruption of the B(0⁺) state above υ_B = 3. Spectroscopic constants are given for the D′ and a′ states.     

Light‐triggered antifouling coatings for porous silicon optical transducers

Nanostructured porous silicon (PSi) is an attractive platform for the design of biosensors because of its high sensitivity and selectivity towards various biological targets. Its use for biosensing applications, however, is compromised as a result of interfacial interactions with biological molecules that may accumulate on their surfaces and degrade their performance. We describe a new hybrid system comprising an oxidized PSi (PSiO₂) nanostructure and antifouling (anti‐adsorption), light‐triggered pre‐polymers that promote crosslinking and surface anchoring to Si walls. The incorporation of the pre‐polymers allowed the production of a thick hydrogel layer on the inorganic nanostructure. Coating completely prevents fouling of proteins on the surface without compromising biosensor performance in terms of sensitivity. The strategy developed here provides a convenient means to combine two distinct features of crosslinking and organic–inorganic hybrid fabrication in a “one‐pot” process. Copyright © 2017 John Wiley & Sons, Ltd.     

Chemical structure evolution of acrylic-melamine thermoset upon photo-ageing

This article reports a study of the influence of UV light irradiation in the presence of oxygen on both the chemical structure evolution and mechanical properties of an acrylic-melamine (AM) thermoset. Photo-oxidation of the thermoset was investigated by several techniques, such as IR spectroscopy, DMA, headspace-SPME and atomic force microscopy (AFM). The measurements by infrared spectroscopy combined with gas analysis allowed us to elucidate details of the reaction mechanisms that are difficult to detect by only spectroscopic measurements. This approach was used to probe mechanistic aspects of the photo-oxidation of acrylic-melamine (AM) thermoset and was completed by dynamic-mechanical measurements combined with AFM and micro-hardness measurements, which revealed the effect of photo-oxidation on the mechanical properties of the thermoset.     

Meson production inp+U,O+U and S+U interactions at 200 GeV/nucleon

Meson production in proton, oxygen and sulphur interactions with uranium targets at 200 GeV/nucleon is studied. We measure the inclusive meson cross-section d /dP _T ² and its evolution fromp+U to S+U. The cross-section fitted with an exponential gives an inverse slopeP _T0 of the order of 210 MeV/c. As a function of the neutral transverse energy,P _T0 values show a slight rise followed by a plateau. The normalized difference (⁺–^–)/^– between positive and negative meson cross-sections is found to increase withE _T .also at ISEL     

Semiotic mediation: fragments from a classroom experiment on the coordination of spatial perspectives

In this paper, I shall discuss some fragments from a teaching experiment on the coordination of spatial perspectives, carried out in several 1st and 2nd grade classrooms over the last twenty years and now being tested also in pre-primary schools. The experiment is framed by an interpretation of semiotic mediation after a Vygotskian perspective (Bartolini Bussi and Mariotti 2007), where drawing, language (in both its oral and written form), gestures and symbolic play are related to each other. The paper is divided into two parts. In the first, some data from the experiment are presented to describe the long term process of internalization of tools in real life drawing, considered as a problem solving task. In the second part, the outcomes will be reconsidered to describe a theoretical perspective, common to other teaching experiments, for the realization of processes of semiotic mediation in the mathematics classroom.