A literature review comprising 163 publications published over a period of 26 years from 1992 to 2018 is presented in this paper. This review discusses the generation and recycling of construction and demolition waste (CDW) as well as its main uses as raw materials for the construction engineering sector. This review pays attention to the use of CDW aggregates for sand, pavements/roads, bricks, ceramics, cementitious materials, and concrete productions, as well its uses as eco-friendly materials for water decontamination. The physical-chemical and mechanical characteristics of recycled aggregates play an important role in their correctly chosen applications. The results found in this literature survey allow us to conclude that recycled aggregates from CDW can be successfully used to produce construction materials with quality comparable to those produced with natural aggregates. We concluded that the use of CDWs as raw materials for manufacturing new construction materials is technically feasible, economical, and constitutes an environmentally friendly approach for a future construction and demolition waste management strategy.

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For centuries, jigging has been a workhorse of the mineral processing industry. Recently, it has also found its way into the recycling industry, and the increasing concerns related to water usage has led to a renewed interest in dry jigging. However, the current scenario of increasing ore complexity and the advent of smart sensor technologies, such as sensor-based sorting (SBS), has established increasingly challenging levels for traditional concentration methods, such as jigging. Against this background, the current review attempts to summarize and refresh the key aspects and concepts about jigging available in the literature. The configuration, operational features, applications, types, and theoretical models of jigging are comprehensively reviewed. Three promising paths for future research are presented: (1) using and adapting concepts from granular physics in fundamental studies about the stratification phenomena in jigs; (2) implementing advanced control functions by using machine vision and multivariate data analysis and; (3) further studies to unlock the potential of dry jigs. Pursuing these and other innovations are becoming increasingly essential to keep the role of jigging as a valuable tool in future industry.

a b s t r a c tThe use of ethanol as fuel has encouraged many countries to improve their production processes. However, costs related to its current production model have been occasionally mentioned as a disadvantage to the use of this biofuel. One of the main costs is the energy expenditure for an effective distillation of the fermented ethanol wort, to result a final product called hydrous ethanol (about 95% by volume of ethanol in water). A promising alternative is the use of ethanol fuel with high fractions of water (above 5% by volume), the so-called wet ethanol, which would reduce the energy cost of production during the distillation. Thus, this study proposes the development of a mathematical model that, along with experimental data, is able to predict the effect that the use of wet ethanol has on the performance of internal combustion engines. In order to do so, along with commercial hydrous ethanol, blends were prepared with the following volume fractions of water: 10% (E90W10), 20% (E80W20), 30% (E70W30) and 40% (E60W40). Tests were performed considering two engine operating conditions: (a) fixed ignition timing and (b) adjusted ignition timing for maximum engine torque. The model was able to successfully simulate the gradients of pressure and temperature in the cylinder and it showed good ability to predict engine performance based on the variations of power, torque, conversion efficiency, and specific fuel consumption. Except for the specific fuel consumption, where the estimated error for variations was greater than 20%, the estimates for the other performance parameter presented relative errors lower than 7%. For all tests, the relative error was lower than 13%. The gradual increase of specific fuel consumption was associated with the increasing water content. Among the fuels tested, E70W30 showed the best performance, followed by the E80W20 blend; both were more efficient than the commercial ethanol.

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