Thermal transformation of micro-crystalline cellulose in phosphoric acid

Use of crude oil derivatives such as diesel and gasoline is becoming unsuitable due to their detriment to environment and to the increasing worldwide energy demand which is driving crude oil reservoirs towards exhaustion. Replacement of diesel and gasoline with biofuels (i.e. biodiesel and bioethanol, respectively) is very desirable. In fact, biofuels are not only environmentally sustainable, but also potentially inexhaustible due to the large amounts of waste biomasses from which they can be retrieved. In the present study, a model compound (micro-crystalline cellulose) was dissolved in phosphoric acid and converted at 80 °C to glucose, thereby providing the possible substrate for fermentation to bioethanol. Results revealed that after 1 h heating, the reaction had the largest glucose yield as compared to similar studies done by using other acid catalysts. In addition, the temperature applied here was from 40 to 60 °C lower than those already reported in literature for acid-driven cellulose degradations. Phosphoric acid allowed both glucose and levulinic acid achievement. The latter is usually used to synthesize fuel additives, catalysts, solvents and herbicides, thereby enhancing the added value of the conversion of cellulose to glucose in phosphoric acid. Finally, ¹H T₁ NMR relaxometry showed its suitability to monitor cellulose degradation. The advantages of relaxomety are its quickness since only few minutes are needed to obtain relaxograms, and the possibility to use raw mixtures without the needing of sample preparation.     

An effective heuristic for large-scale capacitated facility location problems

The Capacitated Facility Location Problem (CFLP) consists of locating a set of facilities with capacity constraints to satisfy the demands of a set of clients at the minimum cost. In this paper we propose a simple and effective heuristic for large-scale instances of CFLP. The heuristic is based on a Lagrangean relaxation which is used to select a subset of “promising” variables forming the core problem and on a Branch-and-Cut algorithm that solves the core problem. Computational results on very large scale instances (up to 4 million variables) are reported.     

Metric inequalities and the Network Loading Problem

Given a simple graph G(V,E) and a set of traffic demands between the nodes of G, the Network Loading Problem consists of installing minimum cost integer capacities on the edges of G allowing routing of traffic demands.In this paper we study the Capacity Formulation of the Network Loading Problem, introducing the new class of Tight Metric Inequalities, that completely characterize the convex hull of the integer feasible solutions of the problem.We present separation algorithms for Tight Metric Inequalities and a cutting plane algorithm, reporting on computational experience.     

Quantitative Label-Free Comparison of the Metabolic Protein Fraction in Old and Modern Italian Wheat Genotypes by a Shotgun Approach

Wheat represents one of the most important cereals for mankind. However, since wheat proteins are also the causative agent of several adverse reactions, during the last decades, consumers have shown an increasing interest in the old wheat genotypes, which are generally perceived as more “natural” and healthier than the modern ones. Comparison of nutritional value for modern and old wheat genotypes is still controversial, and to evaluate the real impact of these foods on human health comparative experiments involving old and modern genotypes are desirable. The nutritional quality of grain is correlated with its proteomic composition that depends on the interplay between the genetic characteristics of the plant and external factors related to the environment. We report here the label-free shotgun quantitative comparison of the metabolic protein fractions of two old Sicilian landraces (Russello and Timilia) and the modern variety Simeto, from the 2010–2011 and 2011–2012 growing seasons. The overall results show that Timilia presents the major differences with respect to the other two genotypes investigated. These differences may be related to different defense mechanisms and some other peculiar properties of these genotypes. On the other hand, our results confirm previous results leading to the conclusion that with respect to a nutritional value evaluation, there is a substantial equivalence between old and modern wheat genotypes. Data are available via ProteomeXchange with identifier <PXD024204>.     

The inorganic fraction in e-liquids used in vapor products including e-cigarettes

Journal of Radioanalytical and Nuclear Chemistry - Nowadays, e-cigarettes are largely used, they are considered less dangerous than the traditional cigarettes. Actually, there are a lot of...