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.     

Arzelà-Ascoli theorem via the Wallman compactification

In the paper, we recall the Wallman compactification of a Tychonoff space T (denoted by Wall(T)) and the contribution made by Gillman and Jerison. Motivated by the Gelfand-Naimark theorem, we investigate the homeomorphism between C^b(T), the space of continuous and bounded functions on T , and C(Wall(T)), the space of continuous functions on the Wallman compactification of T. Along the way, we attempt to justify the advantages of the Wallman compactification over other manifestations of the Stone-?ech compactification. The main result of the paper is a new form of the Arzelà-Ascoli theorem, which introduces the concept of equicontinuity along ω-ultrafilters.     

The evolution of the molecular relaxation parameters described by the Cole–Cole model at the isotropic-nematic phase transition*

This paper presents the dielectric properties of the isotropic liquid and nematic phase at the phase transition. One strong molecular relaxation is observed in both phases. It is interpreted as related to the relaxation around a short molecular axis, due to the fact that molecules possess a strong longitudinal dipole moment. In the isotropic liquid the relaxation is described by the Debye model, while after entering the nematic phase (at cooling) relaxation becomes described by the Cole–Cole model. The distribution parameter of the Cole–Cole model changes from 0.05 (10 degrees above the temperature of the Iso-N transition) to 0.09 (exactly at the phase transition Iso-N), and finally, it reaches 0.35 (10 degrees below the Iso-N transition). Additionally, we observe that ion contribution to the dielectric response is not influenced by the phase transition. All relaxation parameters are discussed within the context of the phase transition phenomena.     

Quantum Tunneling Mediated Interfacial Synthesis of a Benzofuran Derivative

Reaction pathways involving quantum tunneling of protons are fundamental to chemistry and biology. They are responsible for essential aspects of interstellar synthesis, the degradation and isomerization of compounds, enzymatic activity, and protein dynamics. On‐surface conditions have been demonstrated to open alternative routes for organic synthesis, often with intricate transformations not accessible in solution. Here, we investigate a hydroalkoxylation reaction of a molecular species adsorbed on a Ag(111) surface by scanning tunneling microscopy complemented by X‐ray electron spectroscopy and density functional theory. The closure of the furan ring proceeds at low temperature (down to 150 K) and without detectable side reactions. We unravel a proton‐tunneling‐mediated pathway theoretically and confirm experimentally its dominant contribution through the kinetic isotope effect with the deuterated derivative.     

Polyethylene green composites modified with post agricultural waste filler: thermo-mechanical and damping properties

The aim of the study was to determine thermo-mechanical properties and applicability of sunflower husk waste as a filler for ultra low density polyethylene composites. The post agricultural waste filler was milled and chemically treated with (3-aminopropyl)triethoxysilane (3-APS). The amount of filler used was 5, 10 and 20 wt%. The mechanical and thermal properties of the composites containing unmodified and modified natural fillers were determined in the course of static tensile test, rebound resilience by Schob method, and dynamic mechanic thermal analysis. The influence of filler loading and chemical modification of the filler on the morphology of natural composites was evaluated by SEM analysis.     

Reversible Speed Regulation of Self-Propelled Janus Micromotors via Thermoresponsive Bottle-Brush Polymers

This work reports a reversible braking system for micromotors that can be controlled by small temperature changes (≈5 °C). To achieve this, gated-mesoporous organosilica microparticles are internally loaded with metal catalysts (to form the motor) and the exterior (partially) grafted with thermosensitive bottle-brush polyphosphazenes to form Janus particles. When placed in an aqueous solution of H₂O₂ (the fuel), rapid forward propulsion of the motors ensues due to decomposition of the fuel. Conformational changes of the polymers at defined temperatures regulate the bubble formation rate and thus act as brakes with considerable deceleration/acceleration observed. As the components can be easily varied, this represents a versatile, modular platform for the exogenous velocity control of micromotors.     

Conformational Space and Stability of ETD Charge Reduction Products of Ubiquitin

Owing to its versatility, electron transfer dissociation (ETD) has become one of the most commonly utilized fragmentation techniques in both native and non-native top-down mass spectrometry. However, several competing reactions—primarily different forms of charge reduction—occur under ETD conditions, as evidenced by the distorted isotope patterns usually observed. In this work, we analyze these isotope patterns to compare the stability of nondissociative electron transfer (ETnoD) products, specifically noncovalent c/z fragment complexes, across a range of ubiquitin conformational states. Using ion mobility, we find that more extended states are more prone to fragment release. We obtain evidence that for a given charge state, populations of ubiquitin ions formed either directly by electrospray ionization or through collapse of more extended states upon charge reduction, span a similar range of collision cross-sections. Products of gas-phase collapse are, however, less stabilized towards unfolding than the native conformation, indicating that the ions retain a memory of previous conformational states. Furthermore, this collapse of charge-reduced ions is promoted if the ions are ‘preheated’ using collisional activation, with possible implications for the kinetics of gas-phase compaction.

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Oxatriphyrins(2.1.1) Incorporating an ortho‐Phenylene Motif

An understanding of fundamental aspects of archetypal organic structural motifs remains a key issue faced by the experimental and theoretical chemists. Two possible bonding modes for a disubstituted benzene ring, that is a meta and para, determines the π delocalization for oligomeric structures. When the less abundant ortho‐substituted variant is introduced into a triphyrin(2.1.1) skeleton an aromatic molecule is obtained and the carbocyclic ring participates in the conjugation of the macrocycle. The two‐electron reduction and introduction of boron(III) changes the aromatic character and results in an anti‐aromatic structure which has been confirmed by single‐crystal analysis and supported by theoretical calculations.