Search

The worrying and constant increase in the quantities of food and beverage industry by-products and wastes is one of the main factors contributing to global environmental pollution. Since this is a direct consequence of continuous population growth, it is imperative to reduce waste production and keep it under control. Re-purposing agro-industrial wastes, giving them new life and new directions of use, is a good first step in this direction, and, in global food production, vegetables and fruits account for a significant percentage. In this paper, brewery waste, cocoa bean shells, banana and citrus peels and pineapple wastes are examined. These are sources of bioactive molecules such as polyphenols, whose regular intake in the human diet is related to the prevention of various diseases linked to oxidative stress. In order to recover such bioactive compounds using more sustainable methods than conventional extraction, innovative solutions have been evaluated in the past decades. Of particular interest is the use of deep eutectic solvents (DESs) and compressed solvents, associated with green techniques such as microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), pressurized liquid extraction (PLE) and pulsed-electric-field-assisted extraction (PEF). These novel techniques are gaining importance because, in most cases, they allow for optimizing the extraction yield, quality, costs and time. [ABSTRACT FROM AUTHOR]

We introduce L-drawings, a novel paradigm for representing directed graphs aiming at combining the readability features of orthogonal drawings with the expressive power of adjacency matrix representations. In an L-drawing, vertices have exclusive x- and y-coordinates and edges consist of two segments, one exiting the source vertically and one entering the destination horizontally. We study the problem of computing L-drawings using minimum ink. We prove its NP-hardness and provide a heuristic based on a polynomial-time algorithm that adds a vertex to a drawing using the minimum additional ink. We performed an experimental analysis of the heuristic which confirms its effectiveness. [ABSTRACT FROM AUTHOR]

Flows over time problems consider finding optimal dynamic flows over a network where capacities and transit times on arcs are given. In this paper we study a multicommodity flow over time problem in which no storage of flow at nodes is allowed and solutions are restricted to loopless flow-paths. We propose an exact algorithm based on a column generation approach for a path-based linear programming model and present the results of a preliminary computational study. [ABSTRACT FROM AUTHOR]

Given an n-vertex graph and two straight-line planar drawings of the graph that have the same faces and the same outer face, we show that there is a morph (i.e., a continuous transformation) between the two drawings that preserves straight-line planarity and consists of O(n) steps, which we prove is optimal in the worst case. Each step is a unidirectional linear morph, which means that every vertex moves at constant speed along a straight line, and the lines are parallel although the vertex speeds may differ. Thus we provide an ecient version of Cairn's 1944 proof of the existence of straight-line planarity-preserving morphs for triangulated graphs, which required an exponential number of steps. [ABSTRACT FROM AUTHOR]

We study the width requirements of LR-drawings of n -node ordered rooted binary trees; these are the drawings produced by a family of tree drawing algorithms introduced by Chan, who showed how to construct LR-drawings with width O (n 0.48). We prove that LR-drawings with minimum width can be constructed in O (n 1.48) time. Further, we show an infinite family of n -node ordered rooted binary trees requiring Ω (n 0.418) width in any LR-drawing and we present the results of an experimental evaluation that allowed us to determine the minimum width of all the ordered rooted binary trees with up to 455 nodes. We also show that, if n -node ordered rooted binary trees have LR-drawings with f (n) width, for any function f (n) , then n -vertex outerplanar graphs have outerplanar straight-line drawings in O (f (n)) area. Finally, we prove that every n -vertex outerplanar graph has an outerplanar straight-line drawing in O (n ⋅ 2 2 log 2 ⁡ n log ⁡ n) area. [ABSTRACT FROM AUTHOR]