Codes defined by forms of degree 2 on non-degenerate Hermitian varieties in $${\mathbb{P}^{4}(\mathbb{F}_q)}$$

We study the functional codes of second order on a non-degenerate Hermitian variety as defined by G. Lachaud. We provide the best possible bounds for the number of points of quadratic sections of . We list the first five weights, describe the corresponding codewords and compute their number. The paper ends with two conjectures. The first is about minimum distance of the functional codes of order h on a non-singular Hermitian variety . The second is about distribution of the codewords of first five weights of the functional codes of second order on a non-singular Hermitian variety .      

Normal cone approximation and offset shape isotopy

This work addresses the problem of the approximation of the normals of the offsets of general compact sets in Euclidean spaces. It is proven that for general sampling conditions, it is possible to approximate the gradient vector field of the distance to general compact sets. These conditions involve the μ-reach of the compact set, a recently introduced notion of feature size. As a consequence, we provide a sampling condition that is sufficient to ensure the correctness up to isotopy of a reconstruction given by an offset of the sampling. We also provide a notion of normal cone to general compact sets that is stable under perturbation.     

Microfluidic-based electrochemical genosensor coupled to magnetic beads for hybridization detection

This paper describes the development of a rapid and sensitive enzyme-linked electrochemical genosensor using a novel microfluidic-based platform. In this work, hybridization was performed on streptavidin-coated paramagnetic micro-beads functionalized with a biotinylated capture probe. The complementary sequence was then recognized via sandwich hybridization with a capture probe and a biotinylated signaling probe. After labeling the biotinylated hybrid with a streptavidin-alkaline phosphatase conjugate, the beads were introduced in a disposable cartridge composed of eight parallel microchannels etched in a polyimide substrate. The modified beads were trapped with a magnet addressing each microchannel individually. The presence of microelectrodes in each channel allowed direct electrochemical detection of the enzymatic product within the microchannel. Detection was performed in parallel within the eight microchannels, giving rise to the possibility of performing a multiparameter assay. Quantitative determinations of the analyte concentrations were obtained by following the kinetics of the enzymatic reaction in each channel. The chip was regenerated after each assay by removing the magnet and thus releasing the magnetic beads. The system was applied to the analytical detection of PCR amplified samples with a RSD% = 6. A detection limit of 0.2 nM was evaluated.     

A new titanate/(+)-(1R,2S)-cis-1-amino-2-indanol system for the asymmetric synthesis of (S)-tenatoprazole

Tenatoprazole, a substituted imidazopyridinyl derivative, is an irreversible proton pump inhibitor (PPI), which is used for the prevention and treatment of gastric acid-related diseases. A new highly efficient asymmetric oxidation using cumene hydroperoxide (CHP) as the oxidant in the presence of titanium tetraisopropoxide (Ti(OiPr)₄) and (+)-(1R,2S)-cis-1-amino-2-indanol, in a polar aprotic solvent at 0-20 °C, has been developed to prepare tenatoprazole with an enantiomeric excess of >99%, a chemoselectivity of >90% and a chemical yield of >90% from the corresponding sulfide. This procedure was successfully implemented on scales ranging from 100 mg to multiple kilograms. Detailed studies of the parameters controlling purity and yield for this reaction are presented.     

Pressure-induced delocalization of photoexcited states in a semiconducting polymer

We present broadband transient absorption spectroscopy on the fluorescent copolymer poly(9,9-dioctylfluorene-co-benzothiadiazole) under hydrostatic pressure of up to 75?kbar. We observe a strong reduction of the stimulated emission intensity under pressure, coupled with slower decay kinetics and reduced fluorescence intensity. These observations indicate increased delocalization of photogenerated singlet excitons, facilitated by an increased dielectric constant at high pressure. Spin triplet excitons, generated via an iridium complex-F8BT oligomer, show reduced lifetimes under pressure.     

Three-sublattice ordering of the SU(3) Heisenberg model of three-flavor fermions on the square and cubic lattices

Combining a semiclassical analysis with exact diagonalizations, we show that the ground state of the SU(3) Heisenberg model on the square lattice develops three-sublattice long-range order. This surprising pattern for a bipartite lattice with only nearest-neighbor interactions is shown to be the consequence of a subtle quantum order-by-disorder mechanism. By contrast, thermal fluctuations favor two-sublattice configurations via entropic selection. These results are shown to extend to the cubic lattice, and experimental implications for the Mott-insulating states of three-flavor fermionic atoms in optical lattices are discussed.     

Recent Advances and Challenges in the Design of Organic Photoacid and Photobase Generators for Polymerizations

Photopolymerization, or the use of light to trigger polymerization, is one of the most exciting technologies for advanced manufacturing of polymers. One of the key components in the photopolymerization processes is the photoactive compound that absorbs the light, generating the active species that promotes the polymerization and largely determines the final properties of the material. The field of photopolymerization has been dominated by photoradical generators to mediate radical reactions. In the last decade, to expand the number of polymers that can be prepared by photopolymerization, intensive research has been devoted to the synthesis and utilization of photoactive molecules that are able to generate a base or an acid upon irradiation. These organic compounds are known to promote not only the ring‐opening polymerization of various heterocyclic monomers such as lactones, carbonates, or epoxides but also to trigger the step‐growth synthesis of polyurethanes. This Minireview highlights the recent advances in the development of organic photobase and photoacid generators, with the aim of encouraging the wider application of these photoactive compounds in the photopolymerization area and to expand the use of these polymers in advanced manufacturing processes.     

Strain‐Promoted 1,3‐Dithiolium‐4‐olates–Alkyne Cycloaddition

Reported here is the reactivity of mesoionic 1,3‐dithiolium‐4‐olates towards strained alkynes, leading to thiophene cycloaddition products. In the process, the potential of these dipoles towards orthogonal reaction with azides, allowing efficient double ligation reactions, was discovered. A versatile process to access benzo[c]thiophenes, in an unprecedented divergent fashion, was developed and provides a new entry to unconventional polyaromatic thiophenes.     

A new strategy for the numerical modeling of a weld pool

Welding processes involve high temperatures and metallurgical and mechanical consequences that must be controlled. For this purpose, numerical simulations have been developed to study the effects of the process on the final structure. During the welding process, the material undergoes thermal cycles that can generate different physical phenomena, like phase changes, microstructure changes and residual stresses and distortions. But the accurate simulation of transient temperature distributions in the part needs to carefully take account of the fluid flow in the weld pool. The aim of this paper is thus to propose a new approach for such a simulation taking account of surface tension effects (including both the “curvature effect” and the “Marangoni effect”), buoyancy forces and free surface motion.The proposed approach is validated by two numerical tests from the literature: a sloshing test and a plate subjected to a static heat source. Then, the effects of the fluid flow on temperature distributions are discussed in a hybrid laser/arc welding example.