UV-visible Spectra and Gas-Phase Rate Coefficients for the Reaction of 2,3 pentanedione and 2,4-pentanedione with OH Radicals

International audienceThe UV absorption cross-sections of 2,3-pentanedione and 2,4-pentanedione were measured and their reactions with OH were investigated in the gas-phase using a relative rate method. A temperature dependence of the rate coefficients was observed for both reactions over the temperature range 298–338 K. This work provides the first UV cross-section in the gas phase for 2,4-pentanedione and the first kinetic data for the reaction of 2,3-pentanedione with OH radicals as a function of temperature. The tropospheric lifetimes obtained in this work suggest that once emitted into the atmosphere, these species could be quickly degraded close to their emission sources

PLM adoption in SMEs context

The increasing market needs and technologies evolution, push companies to develop competitive advantages based on adequate and intensive use of information technology and communication (ICT). However, SMEs do not realize the importance of ICT adoption, which becomes vital for the development, and are not always well equipped to adopt and integrate them to their activities. The paper focused on issues regarding the ICT adoption, especially PLM solutions by SMEs. By analyzing the PLM definitions and works done, we explored indicators that impact positively or negatively ICT and PLM adoption. This paper proposes a model, currently theoretical, with empirical validation proposal through a survey

UV spectra and kinetic studies of Hydroxycarbonyl compounds reactions with OH radicals

International audienc

DFT analysis and third-harmonic generation properties of one series of push–pull benzylidenemalononitrile derivatives

Optical and nonlinear optical properties of benzylidenemalononitrile derivatives with different electron-donating groups’ substituents were studied. Four benzylidenemalononitrile derivatives [benzylidenemalononitrile (1), (4-chlorobenzylidene)malononitrile (2), (4-hydroxybenzylidene)malononitrile (3) and (4-(dimethylamino)benzylidene)malononitrile (4)] were functionalized, synthesized and analyzed using 1H NMR, FTIR, and UV–vis. A study of electrochemical properties was conducted using cyclic voltammetry. The third-harmonic generation technique was used to analyze and evaluate the susceptibility ($$\chi_{{{\text{THG}}}}^{ }$$) of cubic nonlinear optical properties on thin films at 1064 nm. THG measurements using the Maker fringe technique were used to analyze and evaluate the susceptibility $$\chi_{{}}^{ }$$ parameter of thin films of PMMA with embedded molecules. The studied benzylidenemalononitrile substituted with a strong electron-donating group showed considerable nonlinear responses. Theoretical analysis was performed using DFT/B3LYP/6-311G++ (d, p) and Gaussian 09 program quantum chemical calculations. Third-order nonlinear optical response increases proportionally with the electron-donating character of the substituent groups