Sensitizing effect of bio-based chemicals from urban wastes on the photodegradation of azo-dyes

To promote bio-based products for the industry, six bio-organic substances (cHALi) isolated from yard trimmings (green) and food (humid) urban residues aged under aerobic digestion for 0–60 days were investigated for their potential to perform as sensitizers for azo-dyes photodegradation. Ethylorange (EO) was used as probe molecule at 5 mg L^?1 starting concentration and irradiated in a closed Pyrex^® cell with a Xenon (1500 W) lamp and a cut-off filter for wavelengths below 340 nm or in a cylindrical photochemical reactor equipped with a 125 W medium pressure Hg lamp. The cHALi/EO ratio in the starting EO solution varied in the 0–200 (w/w) range. The % dye abatement was found a function of the irradiation time, of the type of cHALi substance and of the cHALi/EO ratio. The best results were achieved with cHALi isolated after 7 days biomass aerobic digestion. Total dye abatement was achieved within relatively short few hours. A progressive dye mineralization was observed under the same experimental conditions. On the contrary no significant degradation was evident for the cHALi substances within the same irradiation time. Several hydroxylated azo compounds were identified as likely responsible of residual color after total EO abatement. The results, coupled to the previously reported good performance of the same cHALi substances as auxiliaries for textile dyeing, augur well for the development of both efficient and environmentally friendly textile dyeing processes.     

Spatial estimates for transient and steady-state solutions in transversely isotropic plates of Mindlin-type

This paper concerns with a state of bending for a linear transversely isotropic plate model based on the Mindlin assumption on the displacement. By using appropriate families of line-integral measures, we are able to establish results about the spatial behaviour of transient and steady-state solutions. All the results are obtained under relaxed hypotheses on the positive definiteness of the elasticity tensor.     

Preparation of 3-substituted-2-pyridin-2-ylindoles: regioselectivity of Larock’s indole annulation with 2-alkynylpyridines

A regioselective Larock approach to 3-substituted-2-pyridin-2-ylindoles from 2-alkynylpyridines and 2-iodoanilines is described herein. The unexpectedly high regioselectivity can be rationalized by a combination of steric, coordinative and electronic effects.     

A variable neighborhood search for the capacitated arc routing problem with intermediate facilities

The capacitated arc routing problem (CARP) focuses on servicing edges of an undirected network graph. A wide spectrum of applications like mail delivery, waste collection or street maintenance outlines the relevance of this problem. A realistic variant of the CARP arises from the need of intermediate facilities (IFs) to load up or unload the service vehicle and from tour length restrictions. The proposed Variable Neighborhood Search (VNS) is a simple and robust solution technique which tackles the basic problem as well as its extensions. The VNS shows excellent results on four different benchmark sets. Particularly, for all 120 instances the best known solution could be found and in 71 cases a new best solution was achieved.     

Weak Riemannian structures on gauge-group orbits

It has been shown recently that the orbit space for the (Sobolev extended) gauge group action admits a stratification into Hilbert manifolds. Here it is shown that these manifolds carry a natural weak Riemannian structure defined by a metric that corresponds to the kinetic part of the Lagrangian considered in heuristic Yang-Mills theories.     

ATRP synthesis and association properties of thermoresponsive anionic block copolymers

Thermosensitive anionic block copolymers of sodium 2‐acrylamido‐2‐methylpropanesulfonate (AMPS) and N‐isopropylacrylamide (NIPAAM) with different block lengths were prepared by atom transfer radical polymerization (ATRP). Controlled polymerization was achieved by using ethyl 2‐chloropropionate (ECP) as initiator and CuCl/CuCl₂/tris(2‐dimethylaminoethyl)amine (Me₆TREN) catalytic system in DMF:water 50:50 (v/v) mixtures at 20 °C. Blocks lengths ranging from 36 to 98 repeating units were obtained. The association properties in aqueous solutions at different NaCl ionic strengths were studied as a function of temperature and polymer concentration by dynamic light scattering, fluorescence spectroscopy, and energy‐filtered transmission electron microscopy. The block copolymers with a higher pNIPAAM/pAMPS ratio formed spherical core‐shell type micelles independently of the ionic strength. The block copolymers with lower pNIPAAM/pAMPS ratio formed core‐shell type micelles at high ionic strength. Larger particles were observed at low ionic strength, which could be due to the formation of vesicles or compound micelles/micellar clusters. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4830–4842, 2008