Renewable energy transition: a market-driven solution for the energy and environmental concerns in Chile

Chile is undergoing a remarkable energy matrix transition to renewable energy. Renewable energies are expanding extraordinarily fast, exceeding earlier predictions. As a result, the country is expected to meet its 2025 goal of generating 20% of its electricity from renewable energy sources quite before. Chile has become one of the first countries in the world with subsidy-free markets, where renewable projects compete directly with other conventional sources. Favorable market conditions and successful policy reforms were keys to fostering this renewable energy development. Although the country has achieved a substantial growth in renewable energy investment in a relatively short period of time, this optimism should be treated with caution. A successful transition requires a combination of a clear decision making, persistent and consistent government policies, and a clear commitment to tackling challenges to accommodate renewable energy in the power system. In this context, this paper analyses the Chilean renewable industry and the required government policies to succeed in this transition. For this purpose, we identify several critical factors that have attracted and that could attract investment to the renewable energy sector and propose key recommendations to effectively address the major challenges faced for the future development of the industry.     

Optimization of constrained multiple-objective reliability problems using evolutionary algorithms

This paper illustrates the use of multi-objective optimization to solve three types of reliability optimization problems: to find the optimal number of redundant components, find the reliability of components, and determine both their redundancy and reliability. In general, these problems have been formulated as single objective mixed-integer non-linear programming problems with one or several constraints and solved by using mathematical programming techniques or special heuristics. In this work, these problems are reformulated as multiple-objective problems (MOP) and then solved by using a second-generation Multiple-Objective Evolutionary Algorithm (MOEA) that allows handling constraints. The MOEA used in this paper (NSGA-II) demonstrates the ability to identify a set of optimal solutions (Pareto front), which provides the Decision Maker with a complete picture of the optimal solution space. Finally, the advantages of both MOP and MOEA approaches are illustrated by solving four redundancy problems taken from the literature.     

Glass container production scheduling through hybrid multi-population based evolutionary algorithm

Driven by a real-world application in the capital-intensive glass container industry, this paper provides the design of a new hybrid evolutionary algorithm to tackle the short-term production planning and scheduling problem. The challenge consists of sizing and scheduling the lots in the most cost-effective manner on a set of parallel molding machines that are fed by a furnace that melts the glass. The solution procedure combines a multi-population hierarchically structured genetic algorithm (GA) with a simulated annealing (SA), and a tailor-made heuristic named cavity heuristic (CH). The SA is applied to intensify the search for solutions in the neighborhood of the best individuals found by the GA, while the CH determines quickly values for a relevant decision variable of the problem: the processing speed of each machine. The results indicate the superior performance of the proposed approach against a state-of-the-art commercial solver, and compared to a non-hybridized multi-population GA.     

Antibacterial activity of decontamination treatments for cattle hides and beef carcasses

There is increasing interest in effective decontamination treatments because healthy food-producing animals can harbor food-borne pathogens and complete prevention of contamination during slaughter can hardly be warranted. Thus we reviewed the available literature and appraised the antibacterial activity of physical, chemical and biological interventions applied on cattle hides and beef carcasses. Based on the evaluated studies, the efficacy of water sprayings, organic acids and their combinations was most frequently investigated for the decontamination of cattle hides and beef carcasses. Most data originated from laboratory-based studies using inoculated samples and extrapolation of these results to commercial practices is restricted. Application of interventions at slaughter plants reduced the bacterial loads on hides and carcasses to some extent, but reductions were clearly lower than those obtained under laboratory conditions. Thus hot water, steam, acetic acid or lactic acid treatment mainly yielded bacterial reductions below two orders of magnitude on carcasses. Under commercial conditions, the use of multiple sequential interventions at different points during slaughter must also be considered in order to enhance the microbiological safety of carcasses. On the other hand, decontamination treatments always must be considered part of an integral food safety system.     

Synthesis of GAP and PAMMO Homopolymers from Mesylate Polymeric Precursors

In azidic binders for solid propellants, the N₃ functionality is introduced by substitution of a halogen or tosyl group, but recently the mesyl group has been suggested as an alternative. The mesylate group has two advantages, mainly related to its small dimensions and low cost. Poly(glycidyl azide) and poly 3-azidomethyl-3-methyl oxetane were prepared by using both tosylate and mesylate precursors. The azidation kinetics were studied at three different temperatures while keeping all other operating parameters the same. The results confirmed the good potential of the mesylate precursors for the production of azidic binders.     

A lateral flow immunoassay for measuring ochratoxin A: Development of a single system for maize,wheat and durum wheat

A quantitative lateral flow immunoassay for the detection of ochratoxin A (OTA) in cereals has been developed. The ready-to-use device includes a nitrocellulose membrane on which capturing reagents are immobilized in spatially confined zones and a conjugate pad on which the antibody labelled with gold nanoparticles is pre-adsorbed. Stabilization of gold labelled antibodies and blocking of non-specific interactions of the nitrocellulose membrane were obtained by using 1% ovalbumin. This, combined with the use of PEG in the extraction of OTA from cereal samples, allows us to level the matrix effects caused by various cereals (maize, wheat and durum wheat). The immunochromatographic assay developed includes a rapid and very simple treatment of samples, which, in addition, does not involve the use of organic solvents and allows the quantitative determination of OTA with limits of detection as low as 1.5 μg kg^?1. The coefficients of inter–assay variations are below 20%, with recoveries which ranged from 87 to 119%. Fifteen maize samples, four wheat and six durum wheat samples were extracted with the aqueous medium and analysed by the developed assay. A good correlation was observed (y = 0.99 x + 0.18, r² = 0.982, n = 25) when data was compared with that obtained through a reference method.     

A simplified method for the analysis of incremental collapse of reinforced concrete arches

An already known, but so far unpublished, remark is considered[10]. According to it the Heyman simplification for the limit design of a masonry arch can be accepted also for the limit design of a reinforced-concrete arch (when some assumptions are satisfied).With these same assumptions, the same simplification can lead to the calculation of the plastic safety factor of a reinforced-concrete arch liable to incremental collapse under the action of several sets of live loads (moving load, temperature change, earthquake) that can be repeated in an arbitrary manner.An example is given showing good agreement with exact theory.     

Studying Bluetooth Malware Propagation: The BlueBag Project

Current Bluetooth worms pose relatively little danger compared to Internet scanning worms?but things might change soon. The authors' BlueBag project shows targeted attacks through Bluetooth malware using proof-of-concept codes and devices that demonstrate their feasibility.