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Refuse derived fuel (RDF) was subject to torrefaction in order to produce a char with higher homogeneity and lower moisture content than the RDF raw materials. The resulting product, RDF char, showed increased fixed carbon and ash contents, decreased moisture and volatile matter contents, and a very significant increase in density. The torrefaction of RDF may therefore contribute to reduce the landfill volume needed to accommodate these materials to one third of the presently used. This new char material was also tested for its adsorption capacities and the results show that it could be used for the removal of chromium and aluminum from aqueous solutions.

Biofuels provide high oxygen content for combustion and do modify properties that influence the engine operation process such as viscosity, enthalpy of vaporization, and cetane number. Some requirements of performance, fuel consumption, efficiency, and exhaust emission are necessary for the validation of these biofuels for application in engines. This work studies the effects of the use of diethyl ether (DEE) in biodiesel-ethanol blends in a DI mechanical diesel engine. The blends used in the tests were B80E20 (biodiesel 80%-ethanol 20%) and B76E19DEE5 (biodiesel 76%-ethanol 19%-DEE 5%). Fossil diesel (D100) and biodiesel (B100) were evaluated as reference fuels. The results revealed similar engine efficiencies among tested fuels at all loads. The use of B100 increased CO and NOx and decreased THC compared to D100 at the three loads tested. B80E20 fuel showed an increase in NOx emission in comparison with all fuels tested, which was attributed to higher oxygen content and lower cetane number. THC and CO were also increased for B80E20 compared to B100 and D100. The use of B76E19DEE5 fuel revealed reductions in NOx and CO emissions, while THC emissions increased. The engine efficiency of B76E19DEE5 was also highlighted at intermediate and more elevated engine load conditions.

The Elastic Modulus Measurement through Ambient Response Method (EMM-ARM) is designed to continuously monitor the elastic modulus of hardening construction materials such as concrete, cement paste, mortars, stabilized soils, and epoxy resin. In practice, a composite beam, made of the tested material in its mould, is induced to vibration by means of environmental or controlled excitation, and its resonant frequency is identified. The material’s elastic modulus can then be calculated based on the vibration equation of structural systems. The traditional system to conduct EMM-ARM experiments is based on specialized equipment and on proprietary licensed software, which results in a considerable cost, as well as limited options for customization. The paper hereby presented proposes a delve into the development and validation of a cost-effective and open-source system that is able to conduct EMM-ARM experiments. By using a Raspberry Pi for the computing device and cost-effective electronic components, the cost of the system was one-twentieth of the traditional one, without compromising the measurement reliability. The composite beam’s excitation is generated, while the vibration response is recorded by the proposed system simultaneously, since the Raspberry Pi supports multiprocessing programming techniques. The flexibility earned by the exclusive use of open-source and cost-effective resources creates countless application possibilities for the proposed system.

In the actual competitive arena, competition occurs among supply chains, which must be globally resilient and sustainable [...]

Abstract Wood and other bio-based building materials are often perceived as a good choice from a climate mitigation perspective. This article compares the life cycle assessment of the same multi-residential building from the perspective of 16 countries participating in the international project Annex 72 of the International Energy Agency to determine the effects of different datasets and methods of accounting for biogenic carbon in wood construction. Three assessment methods are herein considered: two recognized in the standards (the so-called 0/0 method and –1/+1 method) and a variation of the latter (–1/+1* method) used in Australia, Canada, France, and New Zealand. The 0/0 method considers neither fixation in the production stage nor releases of biogenic carbon at the end of a wood product’s life. In contrast, the –1/+1 method accounts for the fixation of biogenic carbon in the production stage and its release in the end-of-life stage, irrespective of the disposal scenario (recycling, incineration orlandfill). The -1/+1 method assumes that landfills offer only a temporary sequestration of carbon. In the –1/+1* variation, landfills and recycling are considered a partly permanent sequestration of biogenic carbon and thus fewer emissions are accounted for in the end-of-life stage. We examine the variability of the calculated life cycle-based greenhouse gas emissions calculated for a case study building by each participating country, within the same assessment method and across the methods. The results vary substantially. The main reasons for deviations are whether or not landfills and recycling are considered a partly permanent sequestration of biogenic carbon and a mismatch in the biogenic carbon balance. Our findings support the need for further research and to develop practical guidelines to harmonize life cycle assessment methods of buildings with bio-based materials.

AbstractNatural ventilation requires no energy consumption, which can constitute 25% of a mechanically ventilated building, and both shape and position of inlets and outlets ventilation openings must be properly designed for better natural ventilation performance. Wind tunnel tests are a reliable tool for the determination of the effect of natural ventilation on buildings. This paper reports on results of wind tunnel tests conducted for the evaluation of the influence of the positioning and type of grid of ventilation modules on a façade system. Three ventilation modules were positioned below the window-sill (ventilated window-sill) and three were positioned above and below the façade. Ventilation modules with grid elements positioned vertically and horizontally were tested. Wind speed measurements that considered single-sided and cross ventilation were taken inside and outside the model for the different façade configurations for the evaluation of the best performance in relation to natural ventilation. The façade system proposed is movable and interchangeable, so that the same basic model can be used for the testing of possibilities for ventilation. The results show the use of six ventilation modules positioned below the window-sill and that form a “ventilated window-sill” with a horizontal grid is the best solution regarding natural ventilation. Such a configuration has proved the grid elements of ventilation modules exert a higher influence on the results than the positioning of modules on the façade. Therefore, better conditions of natural ventilation were obtained with a thin and horizontal positioning of the elements.

An experimental evaluation of a digital control system based on a dual Digital Signal Processor (DSP) architecture is proposed for a three phase Unified Power Quality Conditioner (UPQC). A classical UQPC is constituted by two power conditioners, connected in series and shunted with the power grid, and sharing a common DC-link. In a smart grid scenario of operation, a UPQC will be fundamental for compensating power quality problems, also contributing to improving the efficiency of the electrical grids from a global perspective. The UPQC operation requires a bidirectional energy transfer between the two power conditioners, however, respecting some constraints, they can be controlled independently. In order to take advantage of this characteristic, the control algorithms can be executed on two independent DSPs, without any communication between them and maintaining the operational characteristics of the UPQC. Comparing with the classical control architecture based on a single DSP, with the proposed dual DSP architecture, the computational effort of each DSP is decreased of about 35%, allowing to increase the sampling rate. Therefore, the main advantages of the proposed approach are the minimization of delays caused by the processing time, which are very common in digital control systems, as well as the increment of the UPQC performance. Along the paper, detailed analysis of the processing speed and memory requirements to implement the UPQC control algorithms in both DSPs is presented. The paper also presents a set of detailed experimental results, obtained with a developed 5 kVA laboratory prototype of UPQC, which was used to evaluate the performance of the proposed dual DSP architecture.

Moringa oleifera is an important source of antioxidants, tools in nutritional biochemistry that could be beneficial for human health; the leaves and flowers are used by the population with great nutritional importance. This work investigates the antioxidant activity of M. oleifera ethanolic (E1) and saline (E2) extracts from flowers (a), inflorescence rachis (b), seeds (c), leaf tissue (d), leaf rachis (e) and fundamental tissues of stem (f). The radical scavenging capacity (RSC) of extracts was determined using dot‐blots on thin layer chromatography stained with a 0.4 mm 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) solution; spectrophotometric assays were recorded (515 nm). Antioxidant components were detected in all E1 and E2 from a, b and d. The best RSC was obtained with E1d; the antioxidants present in E2 reacted very slowly with DPPH. The chromatogram revealed by diphenylborinate‐2‐ethylamine methanolic solution showed that the ethanolic extract from the flowers, inflorescence rachis, fundamental tissue of stem and leaf tissue contained at least three flavonoids; the saline extract from the flowers and leaf tissue revealed at least two flavonoids. In conclusion, M. oleifera ethanolic and saline extracts contain antioxidants that support the use of the plant tissues as food sources. Copyright © 2012 John Wiley & Sons, Ltd.

A techno-economic analysis for use of brewer's spent grains (BSG) on a biorefinery concept for the Brazilian case is presented. Four scenarios based on different levels of heat and mass integration for the production of xylitol, lactic acid, activated carbon and phenolic acids are shown. A simulation procedure using the software Aspen Plus and experimental yields was used. Such procedure served as basis for the techno-economic and environmental assessment according to the Brazilian conditions. Full mass integration on water and full energy integration was the configuration with the best economic and environmental performance. For this case, the obtained economic margin was 62.25%, the potential environmental impact was 0.012 PEI/kg products, and the carbon footprint of the processing stage represented 0.96 kg CO2-e/kg of BSG. This result served as basis to draw recommendations on the technological, economic and environmental feasibility for implementation of such type of biorefinery in Brazil.