Types of carbon adsorbents and their production

Peer reviewe

Post-Franco Theatre

In the multiple realms and layers that comprise the contemporary Spanish theatrical landscape, “crisis” would seem to be the word that most often lingers in the air, as though it were a common mantra, ready to roll off the tongue of so many theatre professionals with such enormous ease, and even enthusiasm, that one is prompted to wonder whether it might indeed be a miracle that the contemporary technological revolution – coupled with perpetual quandaries concerning public and private funding for the arts – had not by now brought an end to the evolution of the oldest of live arts, or, at the very least, an end to drama as we know it

Broad-Band Electrical Conductivity of High Density Polyethylene Nanocomposites with Carbon Nanoadditives: Multiwall Carbon Nanotubes and Carbon Nanofibers

A study is presented of the electrical properties of a series of nanocomposites based on high density polyethylene (HDPE) as a matrix and either carbon nanofiber (CNF) or multiwall carbon nanotube (MWCNT) as a nanoadditive. The measurements of the electrical conductivity over a broad-band of frequencies (10-2 > F/Hz > 109)allow improvement of the description of the electrical properties of polymer nanocomposites based on either carbon nanofibers or carbon nanotubes. Despite the lack of a continuous conducting network between particles at low concentrations, the nanocomposites exhibit a significant dc electrical conductivity due to tunnel conduction. At low nanoadditive concentrations, the frequency dependence of the electrical conductivity is mainly caused by the influence of large polymeric gaps between conducting clusters. As nanoadditive concentration increases, the size of the finite size cluster tends to increase and the frequency dependence of the conductivity reflects the features of anomalous diffusion in fractal structures, as expected according to percolation theory. A master curve for the electrical conductivity as a function of frequency can be constructed although, for the investigated nanocomposites, this behavior should be contemplated as a working, rather than as a universal, law.Peer reviewe

Comparison between emissions from the pyrolysis and combustion of different wastes

A comparison between different emission rates of various pollutants obtained from various wastes is presented. The studied wastes were the following: polyethylene (PE), tyres, sewage sludges, polyvinyl chloride (PVC), cotton textiles, polyester textiles, meat and bone meals (MBMs), varnish wastes, olive oil solid waste (pomace), waste lube oils and paper waste. The decomposition of these wastes was studied in a horizontal laboratory scale reactor under fuel-rich conditions, and the analysis of the pollutants evolved comprised several compounds such as light hydrocarbons, polyaromatic hydrocarbons (PAHs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). From the studied wastes, a general behaviour was deduced regarding the evolution of semi-volatile compounds with the increase of temperature, both in pyrolysis and combustion. The results showed that the emissions of some compounds decreased with increasing oxygen ratio. Compounds with this behaviour were mainly volatile hydrocarbons, which were consumed in presence of oxygen. In addition, compounds with oxidized structure were present a maximum with oxygen ratio. Intermediate compounds with very high resistance to the oxygen under the working conditions increased continuously in concentration when the oxygen ratio increased. With reference to behaviour versus temperature there were compounds whose yields decreased with increasing temperature, such as volatile hydrocarbons and semi-volatile compounds. Also some pollutants are promoted at intermediate temperatures, e.g. light hydrocarbons, semi-volatile compounds, many monoaromatic compounds and many polyaromatic hydrocarbons.Financial support from Generalitat Valenciana (Spain) project GV06/069, and the Spanish MCT research project CTQ2005-05262/PPQ