Simultaneous attainment of high electron and ion temperatures in discharges with internal transport barriers in ASDEX upgrade

Internal transport barriers have been demonstrated to exist also under conditions with T(e) approximately T(i) approximately 10 keV and predominant electron heating of the tokamak core region. Central electron cyclotron heating was added to neutral beam injection-heated ASDEX Upgrade discharges with a preexisting internal transport barrier, established through programmed current ramping leading to shear reversal. Compared to a reference internal transport barrier discharge without electron cyclotron resonance heating, the electron heat conductivity in the barrier region was found not to increase, in spite of a fivefold increase in electron heat flux, and also angular momentum and ion energy transport did not deteriorate.     

Sky implementation of modal predictive control in adaptive optics

We present what we believe are the first experimental results obtained with modal linear predictive control of an adaptive optics system operating on sky at a visible wavelength on a 1.52-m telescope (Observatoire de Haute-Provence, France). This system yields substantially better results than optimized integral control: a 30% relative gain in Strehl ratio is measured, even in conditions of low wind speed.     

Perspectives from above and beyond the proton drip-line

This paper will review the dramatic increase in our knowledge of one and two proton unbound nuclei [1] such as recoil decay tagging [2] are revealing unique insights into the structure of nuclei beyond the proton drip-line. These studies of excited states provide complementary information to proton radioactivity studies, particularly regarding the role of deformation [3]. Radioactive beams are being used to study two-proton unbound resonances and to study explosive nuclear astrophysical reactions in the region of the proton drip-line.     

Synthesis and characterization of main-chain thermotropic aromatic polyazomethines with siloxane spacers

New main-chain liquid crystal copolymers have been synthesized in the polyazomethine series from two polycondensation routes (polyhydrosilylation and polyimination). The mesogenic units are separated with siloxane spacers. The obtained copolymers have been characterized by size-exclusion chromatography and NMR and FT-IR spectroscopies; their mesomorphic behavior has been investigated by polarizing microscopy, differential scanning calorimetry and RX diffraction. Moreover, when the polycondensation reactions are carried out in solution or when the copolymers are kept in a solvent, we observed the formation of macrocyclic dimers, which have been isolated and characterized.     

Etude de la reaction de condensation de systeme epoxyde-amine par resonance magnetique nucleaire - synthese de modeles epoxy-amine

This work is an approach to the analysis, by nuclear magnetic resonance of carbon 13, of epoxy-aminated reticulates in the case of aliphatic aminated hardeners: butylamine, ethylene-diamine, diethylenetriamine, triethylenetetramine. In order to characterize the various species formed at each stage of the reaction, and for various types of resin/hardener stoechiometry, the DGEBA (diglycidyl ether of bisphenol A)/polyamine couple has been modeled by characterizing the structures generated during the reactions of phenylglycidylether (PGE) with two aliphatic amines: n-butylamine (BA) and ethylenediamine (EDA). This study deals with the characterization of non-catalysed systems only (or at least systems without added catalyst).     

Synthesis and evaluation of new phosphonic,bisphosphonic and difluoromethylphosphonic acid monomers for dental application

Syntheses of novel 5-(methacryloyloxy)pentylphosphonic acid 1, 5-(methacryloyloxy)pentylidenebisphosphonic acid 2 and 1,1-difluoro-5-(methacryloyloxy)pentylphosphonic acid 3 are described. The ability of these monomers to adhere to hydroxyapatite was demonstrated using ³¹P CP-MAS NMR spectroscopy. Their copolymerization with N,N′-diethyl-1,3-bis(acrylamido)propane (DEBAAP) was investigated with photo differential scanning calorimetry. These mixtures exhibit a significantly higher reactivity than DEBAAP alone. Bisphosphonic acid 2 was shown to be significantly more reactive than monomers 1 and 3. Adhesive properties of these monomers were also studied. Adhesives based on bisphosphonic acid 2 and difluoromethylphosphonic acid 3 provide significantly higher dentin shear bond strength than the one based on phosphonic acid 1.     

Synthesis and polymerization kinetics of acrylamide phosphonic acids and esters as new dentine adhesives

In restorative dentistry, acrylamide monomers bearing phosphonic acid moieties have proved to be useful species for the formulation of dental self‐etch adhesives since they provide enhanced adhesion to hydroxyapatite and are not subject to hydrolysis, thus potentially improving their adhesive durability. Previous studies have demonstrated that phosphonic acid acrylamides increase the rate of photopolymerization of diacrylamide monomers. To understand whether this rate acceleration is specific to the acrylamide function of the monomer, or due to the phosphonic acid group per se, or is applicable only with a crosslinking reaction, we have synthesized several acrylamide and methacrylate monomers bearing phosphonic acid or phosphonate moieties and studied their photopolymerization kinetics. The acrylamide phosphonic acid was found to accelerate the polymerization rate but similar monomers bearing a phosphonate ester group had a much smaller effect. A similar accelerating effect was observed when the phosphonic acid‐based monomers were copolymerized with a monofunctional acrylamide monomer, excluding the possibility that the rate acceleration might be related to the crosslinking process. This rate effect is also observed when a nonpolymerizable organic phosphonic acid is present in the polymerizing medium. We suggest that the increase of the medium polarity is responsible for this rate enhancement effect. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Phosphine‐Free Palladium‐Catalyzed Allene Carbopalladation/Allylic Alkylation Domino Sequence: A New Route to 4‐(α‐Styryl) γ‐Lactams

Free to decide : Various 4‐(α‐styryl) γ‐lactams are synthesized in 61–88 % yield by a phosphine‐free palladium‐catalyzed carbopalladation/allylic alkylation domino sequence (see scheme). The cyclization is totally regio‐ and diastereoselective in favor of the 3,4‐trans‐disubstituted γ‐lactam. The process is successfully applied to the synthesis of a new aza analogue of the naturally occurring lignan (+)‐oxo‐parabenzlactone.