Sustainability improvement of a composite materials' industry through recycling re-engineering process approaches

This case study was aimed at measuring and assessing the potential improvements that couldbe made on the eco-efficiency performance of a composite materials' industry, specifically aglass fibre reinforced plastic (GFRP) pultrusion manufacturing company. For this purpose, allthe issues involved in the pultrusion process of GFRP profiles were analysed, the current ecoefficiency performance of the company was determined, all the procedures applied in theproduction process were revised, and improvement strategies were planned and investigatedwith basis on the performed analysis. The new eco-efficiency ratios were estimated takinginto account the implementation of new proceedings and procedures through re-engineeringthe manufacturing process and recycling approaches. These features lead to significantimprovements on the sequent assessed eco-efficiency ratios, yielding to a more sustainableproduct and manufacturing process of pultruded GFRP profiles

Improving resource efficiency and minimize environmental footprint: a case study preliminary results

Panasqueira Mine (Portugal) has been mainly exploited for wolframite, cassiterite and chalcopyrite (W, Sn, Cu). Through the detailed and careful characterization of tailings with different mineralogy, new invaluable insights into the weathering characteristics of many different minerals will be received, making possible proper risk assessments, and predict which type of tailings might pose severe future environmental risk namely to the Zêzere river. The Zêzere River is an important river and is under the Cabeço do Pião tailings influence. The knowledge and methods acquired will lead to a conceptual model working as guidance to a more sustainable mining in the hereafter.This work of the project Remine was funded with public national funds from FCT under the programme for International Cooperation ERA-NET, supported by ERA-MIN (2011-2015) funded under the EU 7th Framework Programme FP7-NMP having also for partners the Technical University of Luleå (Sweden) and the National Institute for Metals and Radioactive Resources (INCDMRR), Romania.info:eu-repo/semantics/publishedVersio

Surface circulation in the eastern North Atlantic, from drifters and altimetry

A description of the near-surface circulation and its properties is the result of the analysis of a drifting buoy data set in the eastern North Atlantic between the Iberian Peninsula, the Azores, and the Canary Islands. World Ocean Circulation Experiment-Tropical Ocean-Global Atmosphere experiment drifters equipped with holey sock drogues centered at 15 m depth collected a total of 14.4 years of data. The drifters sampled a rather inhomogeneous velocity field with a weak mean flow regime and eddies of different scales. They meandered southward everywhere in the study region, except in the Iberian coastal transition zone north of 41degreesN where they headed northward. The near-surface mean velocity field obtained from the drifter data set shows all important mean currents, including the poleward Portugal Coastal Countercurrent during the fall, winter, and early spring off western and northern Iberia, the southward Portugal Coastal Current, the slow offshore southward flow of the Portugal Current during the whole year, the southwestward Canary Current, and the eastward Azores Current, which extends to the vicinity of the African coast near the Gulf of Cadiz. Maps of the eddy kinetic energy field were obtained from the drifters and from satellite altimetry. It provides the largest part of the total kinetic energy. The rate of dispersion is estimated from the Lagrangian statistics of the drifting buoys. The dispersion of the drifters in the study region is well modeled by a simple description of eddy diffusion assuming homogeneous turbulence. Ensemble mean diffusivities K and the Langrangian integral length scales and timescales (L and T) were obtained for the zonal and meridional directions. The sea surface temperature measured along the drifter trajectories is used to produce estimates of the eddy diffusivity, which is compared with the diffusivity estimates obtained from the theory of Taylor. The eddy diffusivity is found to be approximately proportional to the eddy kinetic energy. Discrete eddies and meanders were observed using drifters and altimetry in order to map and describe their geographical distribution and characteristics in the eastern North Atlantic

Preventing acid mine drainage from mine tailings

Mining activity always has high impact on its surroundings, being waste deposition the cause of multiple and complex problems to the environment. One of them is Acid Mine Drainage (AMD), causing acid water percolation through large areas in the mine site. Portugal was a prosper tungsten producer from the beginning of the 20th century, having its apogee during World War II. Nowadays there are millions of tons of mine residues deposited in either stock piles or in tailing dams, most of them abandoned, and only one mine still producing tungsten. Available experimental tests to evaluate the acid production potential are listed and commented. Fresh tailings from the still active Panasqueira mine were used as a case study. Laboratory scale tests allowed us to predict the AMD potential as well as its kinetics, which constitutes a very important tool in tailings management. Pilot scale experiments tested the effect of different cover types, including an organic compound host of oxygen consumer microorganisms, in preventing and reducing AMD

Laser-Plasma Interactions Enabled by Emerging Technologies

An overview from the past and an outlook for the future of fundamental laser-plasma interactions research enabled by emerging laser systems

A robust plasma-based laser amplifier via stimulated Brillouin scattering

Brillouin amplification in plasma is more resilient to fluctuations in the laser and plasma parameters than Raman amplification, making it an attractive alternative to Raman amplification. In this work, we focus on high plasma densities, n0>ncr/4 , where stimulated Raman scattering is not possible and laser beam filamentation is the dominant competing process. Through analytic theory and multi-dimensional particle-in-cell simulations, we identify a parameter regime for which Brillouin amplification can be efficient while maintaining filamentation of the probe at a controlled level. We demonstrate pump-to-probe compression ratios of up to 72 and peak amplified probe fluences over 1 kJ cm−2 with ≃50% efficiency. High pulse quality is maintained through control of parasitic filamentation, enabling operation at large beam diameters. Provided the pump and probe pulse diameters can be increased to 1 mm, our results suggest that Brillouin amplification can be used to produce sub-picosecond pulses of petawatt power

Optimization of plasma amplifiers

Plasma amplifiers offer a route to side-step limitations on chirped pulse amplification and generate laser pulses at the power frontier. They compress long pulses by transferring energy to a shorter pulse via the Raman or Brillouin instabilities. We present an extensive kinetic numerical study of the three-dimensional parameter space for the Raman case. Further particle-in-cell simulations find the optimal seed pulse parameters for experimentally relevant constraints. The high-efficiency self-similar behavior is observed only for seeds shorter than the linear Raman growth time. A test case similar to an upcoming experiment at the Laboratory for Laser Energetics is found to maintain good transverse coherence and high-energy efficiency. Effective compression of a 10 kJ , nanosecond-long driver pulse is also demonstrated in a 15-cm-long amplifier