A note on a result by M. Bognár concerning the Hahn--Mazurkiewicz Theorem

Summary In this note we use Theorem 2.4 in<span lang=EN-US style='font-size:10.0pt;mso-ansi-language:EN-US'>[1]to give a very short proof of a recent result due to M. Bognár (Theorem A in [3]). We also prove that Bognár's result is in fact equivalent to the classical Hahn-Mazurkiewicz Theorem. Finally we give generalizations in the non-compact setting.     

Determination of bromide by low power surfatron microwave induced plasma after bromine continuous generation

A simple continuous flow generation of volatile bromine is described for the determination of low concentrations of the elements by atmospheric-pressure argon microwave induced plasma (MIP) surfatron. Bromine is continuously generated by mixing the bromide with sulphuric acid and hypochlorite solutions. The bromine vapor is separated from the aqueous phase by a gas-liquid separator and is desiccated by passing it through concentrated sulphuric acid. The detection limit attained was 2 microg/l. and the precision was +/-0.7% (at the 80 microg/l. level). The proposed determination is very selective if oxidizing/reducing agents are absent. The procedure has been tested for bromide determination in two drug preparations. Good agreement between the experimental results and the certified values has been obtained.     

Kinetic study on the homogeneous esterification of acetic acid with isoamyl alcohol

The liquid‐phase esterification of acetic acid and isoamyl alcohol has been studied to develop a kinetic model using a sequential experimental design based on the divergence criterion. Data come from batch reactor experiments, performed in the temperature range of 316–363 K. Discrimination among 36 possible kinetic models, written in terms of activity, mole fractions, and molar densities, is possible through the deviance information criterion, as estimated by a Markov chain Monte Carlo technique. The obtained results indicate a negligible heat of reaction and a clear autocatalytic effect of acetic acid on the esterification rate. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 10–18, 2013     

Calculating Steady States for a Fokker–Planck Equation

We characterize vector fields for which the Fokker–Planck equation with -diffusion has a stationary solution in exponential form. These ideas are extended to every vector field associating to it a sequence of functions in order to generalize such exponential form.     

Effects of crystallographic ordering on the magnetic behaviour of (AgIn)1-zMn2zTe2 and (CuIn)1-zMn2zTe2 alloys

Measurements of magnetic susceptibility in the temperature range 4.2–300 K were made on polycrystalline samples of the (AgIn)_{1 - z}Mn_2zTe₂ and (CuIn)_{1 - z}Mn_2zTe₂ alloys, and the data used to give values of spin-glass transition te mperature T_g and Curie-Weiss paramagnetic temperature θ. For any sample for which the X-ray powder photograph indicated an apparently single phase condition, either zinc-blende or chalcopyrite, the susceptibility data could show up to three separate T_g values. These different magnetic conditions are attributed to crystallographic ordering of the Mn ions on the chalcopyrite and zinc-blende lattices, the three observed T_g values corresponding to disordered zinc-blende, ordered zinc-blende and ordered chalcopyrite. The value of θ obtained from the 1/χ vs. T plot is shown to be a weighted mean of the separate values of θ for the phases present. The relative sizes of the T_g peaks and the values of θ for any given sample gives an indication of the amount of each phase present. These amounts were varied by using different methods of heat treatment and it was shown that the magnetic behaviour was consistent with the T(z) phase diagram for the two alloy systems.     

On a possible interpretation of the X(3872) as a 1<Superscript>1</Superscript>D<Subscript>2</Subscript> state in a constituent-quark model based on a generalized Fermi-Breit equation

A recent experimental analysis suggested to represent the X(3872) -resonance as a c [`(c)] \bar{{c}} 1¹ D ₂ state but this attribution is being hotly debated. We calculate the mass values for that state by means of a previously studied constituent-quark model. The different contributions of the model Hamiltonian to the total mass are also explicitly shown.     

Effect of low-temperature processing on dry film photoresist properties for flexible electronics

This study presents the mechanical characterization of the dry film photoresist PerMX and its adhesion properties when laminated onto Kapton® E (PI) and Melinex® ST506 (PET). Additionally, the processing temperature, the adhesion strength, and the neutral plane position are investigated and optimized. A relatively low-temperature (85 °C) process is developed to protect the integrity of the polymers with low glass transition temperature and reduce the thermal mismatch stress. Reduction in processing temperature led to a decrement in the adhesion strength. To counteract this unwanted effect, surface treatments (oxygen plasma) are performed on the polymer surface before lamination. Using the latter techniques, adhesion of PerMX to PET (hard bake: 1 h at 85 °C) is increased from 0.07 to 0.26 N mm⁻¹ (variation of 270%). Finally, the mechanical robustness is investigated and increased by tuning the position of the neutral plane, after 50,000 bending cycles and a radius of curvature of 2.5 mm. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

Application of a Microwave Helium Plasma Torch Operating at Atmospheric Pressure to Destroy Trichloroethylene

We examined the influence of the gas flow-rate, microwave power and trichloroethylene concentration on the destruction of trichloroethylene with a system based on a microwave helium plasma operating at atmospheric pressure. Based on the experimental results obtained, the proposed system allows input concentrations of C₂HCl₃ in the ppmv range to be reduced to output concentrations in the ppbv range (i.e. virtually quantitative destruction) by using a microwave plasma power below 1000 W. High helium flow-rates and C₂HCl₃ concentrations allow energy efficiency values above 600 g/kW h to be obtained. Analyses of the output gases by gas chromatography and species present in the plasma by optical emission spectroscopy confirmed the negligible presence of halogen compounds resulting from the destruction of C₂HCl₃, and that of CCl₄ and C₂Cl₄ as the sole chlorine species exceeding levels of 30 ppbv. Gaseous by-products consisted mainly of CO₂, NO and N₂O in addition to Cl₂ traces.