Potassium fertilisation and the thermal behaviour of Cynara cardunculus L.

Herbaceous biomass like Cynara is commonly high in potassium, chlorine and ash, which has been reported as a source of problems for combustion applications. An appropriate management of the potassium fertilisation is suggested as a way of improving the quality of the Cynara biomass for solid fuel applications. In this work a factorial experiment was designed involving two types of fertilisers, KCl and K2SO4, and two K rates, in order to study the effect of potassium fertilisation on the composition and thermal behaviour of Cynara biomass. The results proved that the potassium content of Cynara biomass increases with the potassium fertilisation. The thermogravimetric study showed that sintering phenomena can be expected at temperatures higher than 900 °C when the crop has been highly K-fertilised, irrespective of the type of fertiliser used, KCl or K2SO4. However, the SEM images taken of samples of the four K treatments of this experiment did not reveal signs of ash melting, although some particles with crystalline appearance appeared in the samples from highly K-fertilised treatments

Effects of mould wear on hydrophobic polymer surfaces replicated using plasma treated and laser-textured stainless steel inserts

YesThe mass production of polymeric parts with functional surfaces requires economically viable manufacturing routes. Injection moulding is a very attractive option however wear and surface damage can be detrimental to the lifespan of replication masters. In this research, the replication of superhydrophobic surfaces is investigated by employing a process chain that integrates surface hardening, laser texturing and injection moulding. Austenitic stainless steel inserts were hardened by low temperature plasma carburising and three different micro and nano scale surface textures were laser fabricated, i.e. submicron triangular LaserInduced Periodic Surface Structures (LIPSS), micro grooves and Lotus-leaf like topographies. Then, a commonly available talc-loaded polypropylene was used to produce 5000 replicas to investigate the evolution of surface textures on both inserts and replicas together with their functional response. Any wear orsurface damage progressively built up on the inserts during the injection moulding process had a clear impact on surface roughness and peak-to-peak topographies of the replicas. In general, the polymer replicas produced with the carburised inserts retained the wetting properties of their textured surfaces for longer periods compared with those produced with untreated replication masters.European Union’s H2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 675063 (www.laser4fun.eu). The work was also supported by three other H2020 projects, i.e. “HighImpact Injection Moulding Platform for mass-production of 3D and/or large micro-structured surfaces with Antimicrobial, Self-cleaning, Anti-scratch, Anti-squeak and Aesthetic functionalities” (HIMALAIA, No. 766871), “Process Fingerprint for Zero-defect Net-shape Micromanufacturing” (MICROMAN, No. 674801) and “Modular laser based additive manufacturing platform for large scale industrial applications” (MAESTRO, No. 723826). Further support was provided by the UKIERI DST programme “Surface functionalisation for 18/20 Accepted in the journal Tribology – Materials, Surfaces & Interfaces. food, packaging, and healthcare applications

Geometry Characterization of AISI 430 Stainless Steel Microstructuring Using Laser

Laser-generated surface patterns provide the means for local mechanical interlocking between the joined materials, tunes the wettability of surfaces that come in contact, and generally are the main factor for bonding strength enhancement, especially between dissimilar materials. This paper presents the influence of different patterning overlays generated with a pulsed laser on the surface of stainless-steel sheets. For all experiments, an overlapping degree of 90% has been chosen between three different patterns, while the engraving speed, pulse frequency and number of passes have varied. The textured surfaces’ morphology was assessed through optical microscopy, and the roughness of the surfaces was correlated with the corresponding experimental parameters. The results have indicated promising insights for joining stainless steel to plastic materials, which is otherwise difficult to assess through usual welding techniques

Influence of preparation procedure on the conductivity and transparency of SWCNT-polymer nanocomposites

Nanostructuring of polymers has opened up new perspectives for multi-functional materials. In this paper we report on the feasibility of preparing transparent and conducting polymer nanocomposites based on poly(ethylene terephthalate) (PET) and single wall carbon nanotubes (SWCNT) as additive. Polymer nanocomposites were prepared by two different methods, direct mixing in the melt (DM) and in situ polymerization (I-SP). Samples prepared by DM show a low percolation threshold for electric conductivity, φ{symbol}c = 0.024 wt.% of SWCNT, and are more transparent to light than samples prepared by I-SP. Particularly, a DM composite with composition just above φ{symbol}c exhibits a conductivity of ∼10-8 S/cm and about 70% of transmittance to visible light. Better electrical and optical properties of nanocomposites prepared by DM in relation to those prepared by I-SP can be explained by assuming that a certain level of aggregation of SWCNT favors the formation of electrical pathways and reduces the number of scatters of light, hence favoring the transmittance of the visible light through these materials. © 2009 Elsevier Ltd. All rights reserved.Financial support from the Spanish Ministry of Science and Education (Grant MAT2005–01768), Comunidad de Madrid-CSIC (Grant CAM/CSIC:CCG07-CSIC/MAT-2296) and from the Polish Ministry of Science and Higher Education (Grant DFG/83/2006). Ramón y Cajal ProgramPeer Reviewe

Tin–carbon composites as anodic material in Li-ion batteries obtained by copyrolysis of petroleum vacuum residue and SnO2

14 pages, 16 figures, 3 tables.-- Printed version published Jun 2007.Composite materials with tin nanoparticles surrounded by a “muffling” carbon matrix are formed simultaneously by adding 20% SnO2 to a vacuum residue and following carbonisation between 700°C and 1000°C. The primary purpose of the carbonaceous material is the reduction of SnO2, giving rise to SnS and Sn as nanoparticles. The homogenous distribution of both components induces therefore a synergetic effect on the properties of the electrode material, not only from the electrochemical point of view but also from that mechanical. Thus, the carbon matrix hinders the agglomeration of Li–Sn alloys during long term cycling and, simultaneously, tin particles improve the conductivity of the material and increase the overall capacity as compared with the reference carbon. In addition, a CVD treatment increases the performance of the material. Sn-119 Mössbauer and Li-7 MAS NMR spectroscopies allow a detailed study of partially charged/discharged samples and, therefore, the phases, steps and mechanisms occurring during the electrochemical process.The authors are grateful to CICYT for financial support (Contract MAT2005-00374 and contract MAT2001-1694) and M.C. Mohedano for her technical support. We thank to SCAI (UCO Central Service for Research Support in the HRTEM and 7Li NMR characterization). A. Concheso is indebted to MCYT for his predoctoral grant.Peer reviewe

Revista de la Asociación Venezolana de Derecho Marítimo. Nr 12 – 1 De la Segunda Etapa

Editors: Gustavo Adolfo Omaña Parés; María Grazia Blanco; Iván Sabatino Pizzolante La segunda etapa de la revista de la Asociación Marítima Venezolana busca, a través de la participación de articulistas venezolanos y extranjeros, examinar los problemas marítimos tanto de una perspectiva local como universal, a través de ensayos, que se ubican en la sección de doctrina, como de comentarios que se encuentran en la sección de actualidad