First-time lidar measurement of water vapor flux in a volcanic plume

The CO₂ laser-based lidar ATLAS has been used to study the Stromboli volcano plume. ATLAS measured water vapor concentration in cross-sections of the plume and wind speed at the crater. Water vapor concentration and wind speed were retrieved by differential absorption lidar and correlation technique, respectively. Lidar returns were obtained up to a range of 3 km. The spatial resolution was 15 m and the temporal resolution was 20 s. By combining these measurements, the water vapor flux in the Stromboli volcano plume was found. To our knowledge, it is the first time that lidar retrieves water vapor concentrations in a volcanic plume.     

Effect of biotic and abiotic stresses on volatile emission of Achillea collina Becker ex Rchb

This study describes the application of headspace solid-phase microextraction (HS-SPME)–gas chromatography/mass spectrometry (GC/MS) to characterise the volatile fingerprint changes of Achillea collina, induced by aphids' infestation, mechanical damage and jasmonic acid (JA) treatment. The volatile organic compound profiles of A. collina, Prunus persica and Pisum sativum infested by Myzus persicae were also compared. Several changes were observed between control, infested, mechanically damaged and JA-treated plants, and new inducible volatile organic compounds (IVOCs) were emitted in response to biotic or abiotic stresses. Some of these were in common for all stresses and other compounds were in common only for two types of stress. Conversely some IVOCs were emitted only in response to the specific stimuli. The results suggested that there were species-specific and common IVOCs emitted by A. collina, P. persica and P. sativum in response to M. persicae infestation. In conclusion, HS-SPME–GC/MS seems to be a reliable analytical approach to study in vivo plant reaction to external stimuli.     

Numerical analysis of a CO2 SFUR laser cavity

Summary In this paper we present a numerical study of the SFUR (self-filtering unstable resonator) cavity resonant modes and numerical results are compared with the experimental data. The numerical code developed for analysing the SFUR cavity will also allow for studying a wider class of resonators, and is therefore a very useful tool in designing new laser cavities.     

Local properties of geodesics onp-convex sets

Summary We prove some local properties of geodesics on p-convex sets. First of all, we give an intrinsic characterization of geodesic in terms of local minimality for the energy functional. Then, we prove local uniqueness and continuous dependence from extrema for geodesics with assigned endpoints. Further, we show a consequence of these results.     

A long-pulse TE CO2 laser with a negative-branch unstable resonator

Summary A long-pulse (>3 μs) CO₂ laser has been built using a negative-branch, frequency-selective, unstable resonator. The results obtained with this device are shown. The authors of this paper have agreed to not receive the proofs for correction.     

Palladium-catalysed Heck reaction on 1,2-dien-1-ols: a stereoselective synthesis of α-arylated α,β-unsaturated aldehydes

A new methodology for preparing α-arylated α,β-unsaturated aldehydes is reported. The starting materials are all commercially available alkyn-1-ols (1a-c) that have been easily isomerised to the corresponding allenes (2a-c). The key step is the Heck coupling of the 1,2-dien-1-ols with a series of iodo- and bromoarene. The products have been synthesised in good yields, and the reactions were carried out under very mild conditions.     

Local {W^{2,m(\cdot)}_{loc}}regularity for p(.)-Laplace equations

We study ${W^{2,m(\cdot)}_{loc}}$ regularity for local weak solutions of p(·)-Laplace equations where ${p\in C^1(\Omega) \cap C(\overline{\Omega})}$ and ${\min_{x\in \overline{\Omega}} p(x) > 1}$ .     

Synthesis of tetrasubstituted 4,4'-biimidazoles

Highly substituted 4,4'-biimidazoles were synthesized, in good to excellent yields, through a multicomponent imidazole ring synthesis by using imidazol-4-yl-ethane-1,2-diones as starting materials. The obtained compounds were preliminarily tested as chromogenic and fluorescent sensors for heavy metals.