Surface Patterning Increases Fluid Sorption Efficiency in Porous Reactive Coatings: A Model for Optimised Surface-Flow Filtration

Transport in Porous Media - A novel surface-flow filter has been designed to take advantage of a combination of both diffusion and lateral flow permeation, since active coatings, even if porous,...     

Estimation of single-ion anisotropies, crystal-field and exchange interactions in Gd-based frustrated pyrochlore anti-ferromagnets Gd2M2O7 (M=Ti, Sn, Hf, Zr)

The temperature dependence of the experimental results of dc (macroscopic) magnetic susceptibility and nuclear hyperfine properties of frustrated magnetic Gd-based pyrochlore compounds, Gd₂Ti₂O₇, Gd₂Sn₂O₇, Gd₂Hf₂O₇ and Gd₂Zr₂O₇, are analyzed within the frame work of appropriate crystal-field theory and a mean field approximation by introducing effective anisotropic molecular field tensors, and formulating an exact relation between single-ion susceptibility tensors and site susceptibility tensors. Components of the calculated susceptibility along and perpendicular to the local 〈1 1 1〉 axis of the tetrahedral sublattice of pyrochlore structure show that these pyrochlores are easy-planar anisotropic magnetic systems. The crystal-field parameters and anisotropic exchange coupling have been determined and their systematic variations over the Gd-based pyrochlores studied here are discussed.     

Valorization of a By-Product from the Production of Mechanically Deboned Chicken Meat for Preparation of Gelatins

In recent decades, food waste management has become a key priority of industrial and food companies, state authorities and consumers as well. The paper describes the biotechnological processing of mechanically deboned chicken meat (MDCM) by-product, rich in collagen, into gelatins. A factorial design at two levels was used to study three selected process conditions (enzyme conditioning time, gelatin extraction temperature and gelatin extraction time). The efficiency of the technological process of valorization of MDCM by-product into gelatins was evaluated by % conversion of the by-product into gelatins and some qualitative parameters of gelatins (gel strength, viscosity and ash content). Under optimal processing conditions (48–72 h of enzyme conditioning time, 73–78 °C gelatin extraction temperature and 100–150 min gelatin extraction time), MDCM by-product can be processed with 30–32% efficiency into gelatins with a gel strength of 140 Bloom, a viscosity of 2.5 mPa.s and an ash content of 5.0% (which can be reduced by deionization using ion-exchange resins). MDCM is a promising food by-product for valorization into gelatins, which have potential applications in food-, pharmaceutical- and cosmetic fields. The presented technology contributes not only to food sustainability but also to the model of a circular economy.     

Enantioselective Formal C(sp3)−H Bond Activation in the Synthesis of Bioactive Spiropyrazolone Derivatives

Herein, we report the first enantioselective annulation of α‐arylidene pyrazolones through a formal C(sp³)?H activation under mild conditions enabled by highly variable Rh^III‐Cp^x catalysts. The method has a wide substrate scope and proceeds with good to excellent yields and enantioselectivities. Its synthetic utility was demonstrated by the late‐stage functionalization of drugs and natural products as well as the preparation of enantioenriched [3]dendralenes. Preliminary biological investigations also identified the spiropyrazolones as a novel class of Hedgehog pathway inhibitors.     

Two versatile routes towards Cerpegin and analogues: applications of a one pot reaction to new analogues of Cerpegin

Simple and efficient routes to the natural alkaloid Cerpegin and new analogues are described herein. In a first approach, we extend the scope of a one pot three steps reaction, which permits the synthesis of new analogues of Cerpegin, substituted in different ways. In a second line of approach, we present an unprecedented synthesis of Cerpegin and analogues where methylfuranones are condensed with dimethylformamide diethylacetal (DMFDEA) to yield enaminolactone esters, which react easily with various primary amines affording Cerpegin and new analogues. We applied this second approach to the synthesis of new bis-Cerpegins and N-amino-Cerpegins. Most of the syntheses are performed under environmental friendly conditions.     

O−O Bond Formation and Liberation of Dioxygen Mediated by N5‐Coordinate Non‐Heme Iron(IV) Complexes

Formation of the O?O bond is considered the critical step in oxidative water cleavage to produce dioxygen. High‐valent metal complexes with terminal oxo (oxido) ligands are commonly regarded as instrumental for oxygen evolution, but direct experimental evidence is lacking. Herein, we describe the formation of the O?O bond in solution, from non‐heme, N₅‐coordinate oxoiron(IV) species. Oxygen evolution from oxoiron(IV) is instantaneous once meta‐chloroperbenzoic acid is administered in excess. Oxygen‐isotope labeling reveals two sources of dioxygen, pointing to mechanistic branching between HAT (hydrogen atom transfer)‐initiated free‐radical pathways of the peroxides, which are typical of catalase‐like reactivity, and iron‐borne O?O coupling, which is unprecedented for non‐heme/peroxide systems. Interpretation in terms of [Fe^IV(O)] and [Fe^V(O)] being the resting and active principles of the O?O coupling, respectively, concurs with fundamental mechanistic ideas of (electro‐) chemical O?O coupling in water oxidation catalysis (WOC), indicating that central mechanistic motifs of WOC can be mimicked in a catalase/peroxidase setting.     

On Optimality Conditions in Control of Elliptic Variational Inequalities

In the paper we consider optimal control of a class of strongly monotone variational inequalities, whose solution map is directionally differentiable in the control variable. This property is used to derive sharp pointwise necessary optimality conditions provided we do not impose any control or state constraints. In presence of such constraints we make use of the generalized differential calculus and derive, under a mild constraint qualification, optimality conditions in a “fuzzy” form. For strings, these conditions may serve as an intermediate step toward pointwise conditions of limiting (Mordukhovich) type and in the case of membranes they lead to a variant of Clarke stationarity conditions.     

Correlation of green house molecules with global and surface temperature and its effect on environment

A critical analysis has been made on contribution to green house molecules on global warming and surface air temperature rise. The nature of yearly variations of concentrations of green house molecules and global and surface temperature has been presented. Climate change, environmental and economic effects are briefly mentioned. Various diseases caused by global warming are also discussed.