SERS and Raman imaging as a new tool to monitor dyeing on textile fibres

Textile fibres containing Ag nanoparticles have been widely explored for a number of antimicrobial fabrics. Moreover, it is well‐known that textile dyeing is a critical stage in the manufacture thereof. This research shows that surface enhanced Raman scattering (SERS) and Raman imaging can be used with advantage in the monitoring of this process. Using Ag containing linen fibres stained with methylene blue (MB), it was possible to map the local distribution of the MB dye in the fibres by Raman imaging. MB was selected as the SERS molecular probe and as a model dye. Composites of linen fibres and Ag nanoparticles were prepared by distinct methods and used as SERS substrates in order to evaluate the effect of the preparative method on the Raman images. Our results demonstrate that by using Raman imaging associated to the presence of Ag nanoparticles, it is possible to distinguish the local distribution of the dye on the textile surface. This investigation allows to foreseeing the use of this technique in terms of quality control of Ag containing fabrics, which is a market in great expansion. Copyright © 2016 John Wiley & Sons, Ltd.     

Hydrolytically stable arabinofuranoside analogs for the synthesis of arabinosyltransferase inhibitors

The first members of two new families of arabinosyltransferase inhibitors, derived from previously reported hybrid compounds covalently associating an iminoalditol with an α-d-arabinofuranoside, have been prepared. In place of the arabinofuranoside moiety, they incorporate in their structure a suitably substituted tetrahydrofuran (C-glycoside family) or a cyclopentane (carba-sugar family) for mimicking the α-d-arabinofuranoside ring.     

Generic tropical initial ideals of Cohen-Macaulay algebras

We study the generic tropical initial ideals of a positively graded Cohen-Macaulay algebra R over an algebraically closed field k. Building on work of Römer and Schmitz, we give a formula for each initial ideal, and we express the associated quasivaluations in terms of certain I-adic filtrations. As a corollary, we show that in the case that R is a domain, every initial ideal coming from the codimension 1 skeleton of the tropical variety is prime, so “generic presentations of Cohen-Macaulay domains are well-poised in codimension 1.”     

An Interacting Particle Model and a Pieri-Type Formula for the Orthogonal Group

We introduce a new interacting particle model with blocking and pushing interactions. Particles evolve on ?₊ jumping on their own volition rightwards or leftwards according to geometric jumps with parameter q∈(0,1). We show that the model involves a Pieri-type formula for the orthogonal group. We prove that the two extreme cases—q=0 and q=1—lead, respectively, to the random tiling model studied in Borodin and Kuan (Commun. Pure Appl. Math. 67:831–894, 2010) and the random matrix model considered in forthcoming paper of Defosseux (Electr. Commun. Probab., 2012).     

Temporal predictions based on a gradual change in tempo

Previous studies investigating sensitivity to step changes in tempo and prediction of tone onset time have generally utilized isochronous sequences. This study investigates subjects' ability to detect deviations from a gradual change in the tempo of a tone sequence (experiment 1) and their judgment of the perceptually optimal timing of this tone (experiment 2). In experiment 1, inter-onset-intervals within pairs of eight-tone sequences followed a geometric progression to create a gradual tempo change. In one sequence, the final tone was presented either earlier or later than specified by the progression. Subjects performed well at detecting deviations that exaggerated the tempo progression but poorly when it was counteracted. Experiment 2 used similar pairs except that the final tone was always presented earlier in one sequence than the other. Final interval length was adaptively adjusted to subjects' judgments; it was adjudged in best agreement with the progression when its length was roughly half way between the mathematically correct value and the length of the penultimate interval. The data support "multiple-look" and entrainment models of tempo sensitivity and suggest that temporal prediction is based less on the tempo contour of a whole sequence than on the duration of the preceding interval.     

Aerial Vehicle Search-Path Optimization: A Novel Method for Emergency Operations

This paper presents a novel search-path optimization method for moving target search by an aerial vehicle, applicable to realistically sized search areas. For such missions, long endurance vehicles are needed, which are usually fixed-winged. The proposed method accounts for flight kinematics of fixed-wing and rotary-wing aerial vehicles. It additionally accounts for movements of the target, considerably increasing complexity of search-path optimization, compared to a static target. The objective is to maximize the probability to detect a conditionally deterministic moving target within a given time period. We propose a first K-step-lookahead planning method that takes flight kinematic constraints into account and in which the target and platform state space are heterogeneous. It consists of a binary integer linear program that yields a physically feasible search-path, while maximizing the probability of detection. It is based on the Max-K-Coverage problem, as it selects K waypoints while maximizing the probability that a target is within the field of view of a platform at one of these waypoints. This K-step-lookahead planning method is embedded in an iterative framework, where the probability of overlooking a target is fed back to the controller after observations are made. Simulations show the applicability and effectiveness of this method.     

First Long-Distance SRN1 on a propargylic chloride

We report here the first example of a Long-Distance S_RN1 (LD-S_RN1) reaction on a propargylic chloride. The reaction of 1-(3-chloroprop-1-ynyl)-4-nitrobenzene (1) with nitronate anions led to both the formation of the C-alkylation product through an LD-S_RN1 mechanism and the ethylenic compound resulting from nitrous acid elimination on the C-alkylation product 2. In contrast with previous work on LD-S_RN1 reactivity, no O-alkylation product was observed. Only one original product 4 was isolated under phase transfer conditions, resulting from a nucleophilic attack by 2-nitropropane anion on the electrophilic alkyne. This LD-S_RN1 reactivity did not extend to sulfinate anions; the reaction of 1 with sulfinate anions yielded original ethylenic disulfone compounds which were formed via an ionic process.     

Process Parameters Optimization,Characterization, and Application of KOH-Activated Norway Spruce Bark Graphitic Biochars for Efficient Azo Dye Adsorption

In this work, Norway spruce bark was used as a precursor to prepare activated biochars (BCs) via chemical activation with potassium hydroxide (KOH) as a chemical activator. A Box–Behnken design (BBD) was conducted to evaluate and identify the optimal conditions to reach high specific surface area and high mass yield of BC samples. The studied BC preparation parameters and their levels were as follows: pyrolysis temperature (700, 800, and 900 °C), holding time (1, 2, and 3 h), and ratio of the biomass: chemical activator of 1: 1, 1.5, and 2. The planned BBD yielded BC with extremely high SSA values, up to 2209 m²·g⁻¹. In addition, the BCs were physiochemically characterized, and the results indicated that the BCs exhibited disordered carbon structures and presented a high quantity of O-bearing functional groups on their surfaces, which might improve their adsorption performance towards organic pollutant removal. The BC with the highest SSA value was then employed as an adsorbent to remove Evans blue dye (EB) and colorful effluents. The kinetic study followed a general-order (GO) model, as the most suitable model to describe the experimental data, while the Redlich–Peterson model fitted the equilibrium data better. The EB adsorption capacity was 396.1 mg·g⁻¹. The employment of the BC in the treatment of synthetic effluents, with several dyes and other organic and inorganic compounds, returned a high percentage of removal degree up to 87.7%. Desorption and cyclability tests showed that the biochar can be efficiently regenerated, maintaining an adsorption capacity of 75% after 4 adsorption–desorption cycles. The results of this work pointed out that Norway spruce bark indeed is a promising precursor for producing biochars with very promising properties.