Synergistic Catalysis: Enantioselective Addition of Alkylbenzoxazoles to Enals

A novel catalytic enantioselective methodology based on synergistic catalysis is reported. The strategy involves: 1) the metal‐Lewis‐acid activation of alkylazaarenes, and 2) the secondary‐amine activation of enals. Consequently, highly functionalized chiral alkylazaarenes were obtained in good yields and with reasonable stereoselectivity.     

On the influence of the chiral side linking bridge type upon the synclinic vs. anticlinic balance in the case of 2′,3′-difluoroterphenyl derivatives

A homologous series of new ferro- and antiferroelectric liquid crystals, containing 2′,3′-difluorosubstituted terphenyl core as a mesogenic core, has been recently synthesised. Synthetic routes and mesomorphic properties were described. Liquid crystal phases were preliminarily determined by thermomicroscopic and microcalorimetric measurements and verified by dielectric measurements and miscibility methods. Temperatures and enthalpies of phase transitions are given.     

Pristine and Modified Porous Membranes for Zinc Slurry–Air Flow Battery

The membrane is a crucial component of Zn slurry–air flow battery since it provides ionic conductivity between the electrodes while avoiding the mixing of the two compartments. Herein, six commercial membranes (Cellophane™ 350PØØ, Zirfon^®, Fumatech^® PBI, Celgard^® 3501, 3401 and 5550) were first characterized in terms of electrolyte uptake, ion conductivity and zincate ion crossover, and tested in Zn slurry–air flow battery. The peak power density of the battery employing the membranes was found to depend on the in-situ cell resistance. Among them, the cell using Celgard^® 3501 membrane, with in-situ area resistance of 2 Ω cm² at room temperature displayed the highest peak power density (90 mW cm⁻²). However, due to the porous nature of most of these membranes, a significant crossover of zincate ions was observed. To address this issue, an ion-selective ionomer containing modified poly(phenylene oxide) (PPO) and N-spirocyclic quaternary ammonium monomer was coated on a Celgard^® 3501 membrane and crosslinked via UV irradiation (PPO-3.45 + 3501). Moreover, commercial FAA-3 solutions (FAA, Fumatech) were coated for comparison purpose. The successful impregnation of the membrane with the anion-exchange polymers was confirmed by SEM, FTIR and Hg porosimetry. The PPO-3.45 + 3501 membrane exhibited 18 times lower zincate ions crossover compared to that of the pristine membrane (5.2 × 10⁻¹³ vs. 9.2 × 10⁻¹² m² s⁻¹). With low zincate ions crossover and a peak power density of 66 mW cm⁻², the prepared membrane is a suitable candidate for rechargeable Zn slurry–air flow batteries.     

Silver nanoparticles and magnetic beads with electrochemical measurement as a platform for immunosensing devices

The simplicity and analytical utility of silver nanoparticles used as immunolabels with screen-printed measurement electrodes is illustrated by demonstrating an appropriate analytical signal for myoglobin (a protein marker for muscle damage) across a range of concentrations of physiological interest for distinguishing potential myocardial infarctions from normal background levels in serum. Silver nanoparticles were used as labels on one of a pair of anti-myoglobin clones while the other clone was covalently attached to magnetic beads. The two clones were selected so as to bind to different sites on the target protein and allow the formation of complexes containing both magnetic beads and silver nanoparticles. The magnetic beads enabled protein captured from test samples to be separated from other components, while the silver nanoparticles enabled the protein to be quantified. An oxidising potential, applied to screen-printed carbon electrodes, was used to dissolve silver without the need for an external oxidising agent. Silver ions released in the process were subsequently accumulated at the measurement electrodes by applying a suitable reducing potential and, finally, analytical signals were obtained by integrating the charges passed when accumulated silver was stripped from the electrodes by applying a potential ramp. The magnitudes of the measured charges were indicative of the concentrations of myoglobin in each of the test solutions.     

Effective Constructions in Plethysms and Weintraub’s Conjecture

We give a short proof of Weintraub’s conjecture (Weintraub J Algebra 129:103–114, 1990), first proved in Bürgisser et al. (J Algebra 328:322–329, 2011), by constructing explicit highest weight vectors in the plethysms S ^p (?∧?^2q W).     

Kinematics of the motorcar body side deformation process during front-to-side vehicle collision and the emergence of a hazard to car occupants

The kinematics of the process of deformation of the motorcar body side in the culminating phase of a front-to-side vehicle collision has been examined as a possible basis for analyzing and modeling the process of emergence of a hazard to car occupants during a road accident. The course of such accidents has a complex nature and their models are necessarily based on the approximation of non-linear elastoplastic characteristics of impact processes, especially during the transition from the compression phase to the restitution phase of the deformation process. For such characteristics to be obtained, a lot of experimental tests have to be carried out. This paper addresses the short-duration processes with a high degree of complexity.

A front-to-side motorcar collision model has been prepared, which made it possible to analyze the process of deformation of the car body side and the emergence of a hazard and injuries to car occupants. The results of calculation of the deformation rate and range in various car body zones, velocity of the test dummy placed on driver’s seat and velocity of possible dummy’s impact against the car body side being deformed may be taken as a basis for designing effective occupant protection systems. The kinematics of the phase of vehicle contact and deformation process was modeled with taking into account results of experimental tests, including the curves characterizing the largely non-linear processes that are decisive for the deformation of the car body side. The deformation processes analyzed on these grounds showed at the same time the range of penetration of the deformed body part into the car interior, which causes a hazard to vehicle occupants. The calculation results have shown e.g. that the car body side is deformed to a depth of 0.2 m as quickly as within 0.02–0.03 s. At such a car body side deformation range, the car body part being deformed hits occupant’s body in his/her hips and pelvis area with a velocity of about 6 m/s.

     

The effect of gamma irradiation on the structural properties of olivine

Journal of Radioanalytical and Nuclear Chemistry - Gamma irradiation studies of (Mg0.905Fe0.095)2SiO4 olivine were performed using X-ray fluorescence method, X-ray diffraction, Raman and...     

Complete metric approximation property for q-Araki–Woods algebras

By adapting an ultraproduct technique of Junge and Zeng, we prove that radial completely bounded multipliers on q-Gaussian algebras transfer to q-Araki–Woods algebras. As a consequence, we establish the $w^{?}$-complete metric approximation property for all q-Araki–Woods algebras. We apply the latter result to show that the canonical ultraweakly dense C^?-subalgebras of q-Araki–Woods algebras are always QWEP.