On Blow Up Solutions of a Quasilinear Elliptic Equation

Given a bounded regular domain Ω in ℝ^N, we study existence and asymptotic behaviour of the solutions of the equation Δu + |Du|^q = f(u) in Ω, which diverge on ∂Ω. We extend and complete some results contained in [4].     

Duplex‐Stabilization Properties of Oligodeoxynucleotides Containing N2‐Substituted Guanine Derivatives

Oligodeoxynucleotides 3 – 13 carrying different guanine derivatives with substituents at the N² position have been prepared from a common precursor. Duplexes containing these modified bases are more stable than unmodified duplexes. The highest stability is found in guanine derivatives carrying at N² an ethyl and propyl group substituted with a group that is protonated under physiological conditions, which is compatible with a possible interaction of the protonatable group with the phosphates.     

Scaling limits for the Ruijgrok–Wu model of the Boltzmann equation

The Ruijgrok–Wu model of the kinetic theory of rarefied gases is investigated both in the fluid‐dynamic and hydro‐dynamic scalings. It is shown that the first limit equation is a first order quasilinear conservation law, whereas the limit equation in the diffusive scaling is the viscous Burgers equation. The main difficulties came from initial layers that we handle here. Copyright © 2001 John Wiley & Sons, Ltd.     

Exothermal Process in Miscible Polylactide/Poly(vinyl phenol) Blends: Mixing Enthalpy or Chemical Reaction?

Summary: In a previous paper (Macromolecules, 2005 , 38, 9221), the enthalpy of mixing in poly(DL ‐lactide) /poly(vinyl phenol) blends was directly measured by DSC. The first DSC scan for solution/precipitation blends showed phase separation, but miscibility was observed in the second DSC scan. Hence, miscibility was achieved after thermal treatment, an unusual behavior in polymer blend current research. However, the exothermal event observed during the first heating scan could also be the result of a chemical reaction. In this work, a new research study conducted to elucidate the nature of the exothermal heat observed in PDLA/PVPh during the first DSC heating scan. Since the single‐phase PDLLA/PVPh blend obtained after thermal treatment can be redissolved and reprecipitated, results obtained in the consecutive DSC scan prove that the process is completely reversible. Furthermore, GPC and ¹³C NMR results provide evidence that there is no change in the chemical structure of the studied polymers before and after the thermal treatment, which evidences the absence of transesterification reactions. Therefore, it can be concluded that the exothermal heat is the result of a mixing process, and miscibility is a consequence of specific interactions.

New structure expected for transesterfication reactions.     

Ligands Tethering to Biocompatible Ultrasound Active Polymeric Microbubbles Surface

Ultrasound imaging, also known as echography, is a widespread diagnostic tool in medicine. Handiness and versatility are established assets of this non-invasive imaging technique. Echogenic devices enhance the sensitivity of this method and formulations of novel systems is a growing field in biomedical research. In this contribution we describe the synthesis, the mesoscopic characterization, and the functionalization of microbubbles based on telechelic poly (vinyl alcohol) for a next-generation ultrasound imaging multifunctional device suitable for diagnosis as well as for therapeutic purposes.     

Molecular symmetry effects on the stability of highly ordered smectic phases

In an effort to control the phase ranges of highly ordered smectic phases, we examined the impact of molecular symmetry on phase behaviour of a series of 12 symmetrical and unsymmetrical 4,4′-dialkanoyloxybiphenyl derivatives. Combined differential scanning calorimetry, polarised optical microscopy, and X-ray diffraction studies indicated that the compounds studied formed smectic F liquid crystals, and in some cases, G phases at lower temperatures. Although the clearing temperatures were largely unaffected by molecular symmetry, the transitions from the SmF liquid crystals to more ordered phases were consistently lowered upon reducing the molecular symmetry. As a result, unsymmetrical molecules had broader mesophases than their higher symmetry isomers, suggesting a strategy for tuning the phase behaviour of these highly ordered lamellar phases, which have been widely targeted for organic semiconductors.     

Papers by Selected Lecturers at the 11th International Symposium on Non-thermal/Thermal Plasma Pollution Control Technology & Sustainable Energy (ISNTPT 11)

Plasma Chemistry and Plasma Processing -     

Electrophilic Vinylation of Thiols under Mild and Transition Metal-Free Conditions

The iodine(III) reagents vinylbenziodoxolones (VBX) were employed to vinylate a series of aliphatic and aromatic thiols, providing E-alkenyl sulfides with complete chemo- and regioselectivity, as well as excellent stereoselectivity. The methodology displays high functional group tolerance and proceeds under mild and transition metal-free conditions without the need for excess substrate or reagents. Mercaptothiazoles could be vinylated under modified conditions, resulting in opposite stereoselectivity compared to previous reactions with vinyliodonium salts. Novel VBX reagents with substituted benziodoxolone cores were prepared, and improved reactivity was discovered with a dimethyl-substituted core.     

Kinetics and Products of Air Plasma Induced Oxidation in Water of Imidacloprid and Thiamethoxam Treated Individually and in Mixture

Imidacloprid (I) and thiamethoxam (T) are widely used neonicotinoid insecticides with high persistence in the environment and thus included in the watch list of substances for European Union-wide monitoring reported in the Decision 2015/495/EU. In this work aqueous solutions of I, T and I?+?T were subjected to advanced oxidation by air plasma produced by negative DC corona discharges above the liquid surface. The oxidative degradation of each pollutant was investigated by monitoring the rate and the products of its decay when treated alone and in the presence of variable amounts of the other compound. The results show that both I and T are readily degraded and that mineralization can be achieved in this process, as proven by the measurement of the residual organic carbon and by the quantitative conversion of chlorine and sulfur into inorganic chloride and sulfate, respectively. The major organic intermediates formed during the complex stepwise oxidation of I and T were identified and monitored by HPLC–MS/MS analysis. The results of kinetic studies show that both for I and T the reaction rate depends inversely on the insecticide initial concentration, that I and T have similar reactivities and that they do not interfere reciprocally in any specific way when treated in mixture at a total concentration of ca 1?×?10^?4 M. Based on literature data and on previous results with the same reactor, it is reasonable to propose that the oxidation of I and T is initiated by the reaction with OH radicals.