Experimental vapor pressures of 1,2-bis(dimethylamino)ethane, 1-methylmorpholine, 1,2-bis(2-aminoethoxy)ethane and N-benzylethanolamine between 273.18 and 364.97 K

In this work, the experimental vapor pressures of four amines 1,2-bis(dimethylamino)ethane, 1-methylmorpholine, 1,2-bis(2-aminoethoxy)ethane and N-benzylethanolamine using a static apparatus are reported. The temperature range is comprised between 273.18 and 364.97 K and the pressure range between 0.782 Pa and 333 kPa. The molar enthalpies of vaporization at 298.15 K were calculated from Clausius–Clapeyron equation fitted on the experimental results.     

Lattice displacement waves in AuTe2

¹²⁵Te and¹²⁹I Mössbauer spectra were studied of AuTe₂, AuAgTe₄, and AuCuTe₄. A distribution in hyperfine parameters is needed to obtain a satisfactory fit of the¹²⁹I spectra, and is interpreted in favor of lattice displacement waves recently observed in these compounds.     

Effects of Geomaterial-Originated Fillers on Microstructure and Mechanical/Physical Properties of α- and β-Chitosan-Based Films

Edible films and coatings with good mechanical/physical properties are highly required for carrying medical substances and food packaging. So, solvent-cast films of α- or β-chitosan filled with palygorskite, montmorillonite or geopolymer-containing material (GCM), were prepared, and the effects of their clay contents (up to 50 wt.%) on the mechanical/physical properties were assessed. The microstructure of the films was investigated using FT-IR spectroscopy, SEM and thermal analysis. The results showed that, except for the films composed of GCM and β-chitosan, the mechanical properties of the films with limited (up to 5 wt.%) to moderate (5–25 wt.%) amounts of fillers increased as a result of the attractive electrostatic forces formed between the fillers and chitosan functional groups (–NH₃⁺, CH₂OH and NHCOCH₃). However, due to the occurrence of coarse aggregates, the strength of filler-rich films declined. The addition of fillers led to an increase in porosity and water absorption of the films, but it had irregular effects on their wettability and water vapor transmission rate. These observations as well as the thermal stability of the films were discussed in relation to the characterization results.     

Reaction prospecting by 31P NMR: enantioselective rhodium-DuPhos catalysed addition of ZnMe2 to diphenylphosphinoylimines

Chiral shift ³¹P NMR spectroscopy allows the identification of ligand leads in asymmetric catalyst systems for ZnMe₂ addition to ArCHNP(O)Ph₂. Subsequent GC-based optimisation shows [RhCl(CH₂CH₂)₂]₂ and (R,R)-MeDuPhos to be the optimal pre-catalyst combination (product in 78–93% ee). Transmetallation of [(MeDuPhos)Rh{N(P(O)Ph₂–CHMeAr}] with ZnMe₂ appears to be the rate limiting step of the catalytic cycle as competing coordination by the imine starting material leads to Ph₂P(O)NHCH₂Ar via MVP hydrogen-transfer. This limitation can largely be overcome by the slow addition of the imine.     

Improvement of piezoelectric transformer performances using SSHI and SSHI-max methods

The piezoelectric transformers reach densities of power more significant than their magnetic counterparts. However, one of the principal factors limiting the density of power is the acceptable maximum deformation by material constituting the transformer. The heating of the piezoelectric transformers is mainly of mechanical origin. This heating generates a degradation of the characteristics which in its turn generates an additional heating being able to lead to a phenomenon of thermal avalanche. In this work, two nonlinear methods [synchronized switch harvesting on inductor (SSHI) and SSHI-max] have been explored to improve the performance of the Rosen transformer basing on the tension generated by the secondary so as to increase the capacity of mechanic-electric conversion. The simulation results show that SSHI and SSHI-max techniques significantly increase the capacity of mechanic-electric conversion of inserts stuck on a vibrating structure and consequently, the power recovered in electric form. The comparative results of voltage gain, efficiency and the transmitted power of the transformer, before and after SSHI-max and SSHI control are given. These ones indicated that the two nonlinear techniques are promising as applications to improve the performances of the piezo-transformers.     

Low temperature nuclear orientation of149, 151Gd in gadolinium

^{149, 151}Gd fused in gadolinium metal have been oriented at low temperature. The main results are: ¦ (¹⁴⁹Gd,7/2^–¦=0.97(6)_N, ¦(¹⁵¹Gd,7/2^–¦= 0.77(6)_N and I(¹⁴⁹Eu,939 keV)=7/2. Some M1/E2 and E2/M3 mixing ratios in Eu daughter nuclei are also established.     

Optical Features of Catalyst-Free Zinc Oxide Nanostructures Confined to One Dimension

Optics and Spectroscopy - We successfully fabricated polycrystalline zinc oxide catalyst-free nanorods by a successive ion layer adsorption and reaction process. We measured their optical...     

Dry air effects on the copper oxides sensitive layers formation for ethanol vapor detection

The copper oxide films have been deposited by thermal evaporation and annealed under ambient air and dry air respectively, at different temperatures. The structural characteristics of the films were investigated by X-ray diffraction. They showed the presences of two hydroxy-carbonate minerals of copper for annealing temperatures below 250 °C. Above this temperature the conductivity measurements during the annealing process, show a transition phase from metallic copper to copper oxides. The copper oxides sensitivity toward ethanol were performed using conductivity measurements at the working temperature of 200 °C. A decrease of conductivity was observed under ethanol vapor, showing the p-type semi-conducting characters of obtained copper oxide films. It was found that the sensing properties of copper oxide toward ethanol depend mainly on the annealing conditions. The best responses were obtained with copper layers annealed under dry air.     

Nuclear moment determination by Mössbauer effect detection of low temperature nuclear orientation (No/Me)

Absorption Mössbauer spectra were measured on low temperature (6–21 mK) oriented nuclei. For magnetic orientation this method allows the determination of the sign of the parent state magnetic moment. The method enables the determination of the parent state quadrupole coupling even for a polycrystalline sample. Signs of ground state magnetic moments for¹⁹¹Pt and¹⁹³Os, and electric quadrupole moments for¹²⁵Te^m and¹²⁹Te are determined.