Development of atomic beam probe for tokamaks

The concept and development of a new detection method for light alkali ions stemming from diagnostic beams installed on medium size tokamak is described. The method allows us the simultaneous measurement of plasma density fluctuations and fast variations in poloidal magnetic field, therefore one can infer the fast changes in edge plasma current. The concept has been worked out and the whole design process has been done at Wigner RCP. The test detector with appropriate mechanics and electronics is already installed on COMPASS tokamak. General ion trajectory calculation code (ABPIons) has also been developed. Detailed calculations show the possibility of reconstruction of edge plasma current density profile changes with high temporal resolution, and the possibility of density profile reconstruction with better spatial resolution compared to standard Li-BES measurement, this is important for pedestal studies.     

Towards Adaptation to Climate Change: Water for Rice in the Coastal Wetlands of Doñana,Southern Spain

Rice production in coastal wetlands provides critical ecosystem services that range from flood control to wildlife habitat. In the Iberian Peninsula rice was introduced in the 10th Century. Today Iberian rice accounts for about one quarter of the total rice production of the European Union, almost exclusively cultivated in the coastal wetlands of Spain, with permanent flooding. The intensive water management required to produce rice stands at a crucial point since freshwater supply is deteriorating at an unprecedented rate. Here we explore flexible adaptation options to climate change in the Doñana wetlands - a world heritage and biodiversity site - from two points of view: What are the policy options for agricultural water management in view of climate change? How can informed stakeholders contribute to better adaptation? The first question is addressed by simulating water availability to farmers with the WAAPA model under a range of adaptation policy options derived from the view of the local communities. The second question was addressed by means of participatory research. Adaptation options are framed according to the local environmental, social and policy context. Results suggest that perception on the potential role of new water infrastructure and farming subsidies dominates the view of local communities. The choices of the stakeholders that could be simulated with the hydrological model, were quantified in terms of additional water availability for the rice farming, therefore providing a quantitative measure to the qualitative solutions. Information provided during the study shaped the final adaptation options developed. Our research contributes to the definition of sustainable rice production in Europe.     

Photoconduction: Very Large Photoconduction Enhancement Upon Self‐Assembly of a New Triindole Derivative in Solution‐Processed Films (Adv. Funct. Mater. 4/2011)

A new carbazole‐related small molecule exhibiting self‐assembly into ordered nanostructures in solution‐processed cast films has been synthesized and its charge‐photogeneration and ‐transport properties have been investigated. Large photoconductivity was measured in the amorphous state while an enormous improvement in the photoconduction properties was observed when the molecules spontaneously organized. Photocurrents increased upon self‐assembly by up to four orders of magnitude, mostly due to the drastic enhancement of the charge photogeneration. A greatly favorable arrangement of the aromatic cores in the resulting nanostructures, which were characterized by X‐ray analysis, may explain these improvements. Photocurrents of mA cm^?2, on/off ratios of 10⁴ and quantum efficiencies of unity at low field and light intensity, which are among the best values reported to date, along with the simplicity of fabrication, give this readily‐available organic system great potential for use in plastic optoelectronic devices.     

Evaporation of pyrolysis oil: Product distribution and residue char analysis

The evaporation of pyrolysis oil was studied at varying heating rates (～1–10⁶°C/min) with surrounding temperatures up to 850°C. A total product distribution (gas, vapor, and char) was measured using two atomizers with different droplet sizes. It was shown that with very high heating rates (～10⁶°C/min) the amount of char was significantly lowered (～8%, carbon basis) compared to the maximum amount, which was produced at low heating rates using a TGA (～30%, carbon basis; heating rate 1°C/min). The char formation takes place in the 100–350°C liquid temperature range due to polymerization reactions of compounds in the pyrolysis oil. All pyrolysis oil fractions (whole oil, pyrolytic lignin, glucose and aqueous rich/lean phase) showed charring behavior. The pyrolysis oil chars age when subjected to elevated temperatures (≥700°C), show similar reactivity toward combustion and steam gasification compared with chars produced during fast pyrolysis of solid biomass. However, the structure is totally different where the pyrolysis oil char is very light and fluffy. To use the produced char in conversion processes (energy or syngas production), it will have to be anchored to a carrier. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Effect of decreasing platinum amount in Pt–Sn–Ni alloys supported on carbon as electrocatalysts for ethanol electrooxidation

Literature describes the influence of morphological and structural electrocatalysts characteristics, on the catalytic activity toward ethanol electrooxidation. Thus, in this work Pt and ternary Pt–Sn–Ni alloys nanoparticles, supported on Vulcan carbon, were obtained by impregnation/reduction method. The aim of this work was to evaluate the influence of the decrease of platinum and increase of nickel content of the electrocatalysts obtained. The electrocatalysts were characterized by Rutherford backscattering spectroscopy, X-ray diffraction, transmission electronic microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results obtained showed that it was possible to obtain Pt–Sn–Ni nanoparticles with a uniform size distribution in a narrow particle size range with a composition control. Moreover, the simultaneous addition of Sn and Ni to Pt did not affect reticular lattice a value, but the crystallite size decreases significantly. Besides, electrochemical results suggest that the substitution of platinum by nickel, in the electrocalatyst alloys studied, does not compromise the catalytic activity toward ethanol eletrooxidation.     

Degradation assessment of nanostructured superhydrophobic insulating surfaces using multi-stress methods

This paper describes the electrical insulation property of modified superhydrophobic surfaces, which are prepared on epoxy based composites by using special nano-particles. After surface modification the samples exhibit an extreme unwettability with a static contact angle thetasges130deg. In order to investigate the long term stability under multiple stress, the specimens are subjected to electric fields and moisture in accelerated aging tests like modified-rotating-wheel-dipping-test (MRWDT), clean fog test and condensation test, according to the critical outdoor and indoor service conditions, respectively. It is shown that leakage current and effective power dissipation of contamination layers are significantly suppressed in the presence of superhydrophobic insulating surfaces. Thus, the pollution performance of the insulation systems can be enhanced to a great extent in clean fog test and MRWDT, whereas the insulating surfaces covered with nanoparticles seem to have no beneficial effect during the condensation experiments because of the different wetting mode. In addition, the impact of release agents and fillers on the surface superhydrophobicity is also examined in this study. Moreover, the surface analyses are employed to characterize the topographical change of the nanostructure in connection with the material degradation.     

Evaluation of Injectable Composite Material Comprising Biphasic Bone Substitutes and Crosslinked Collagen

Bone tissue engineering has emerged as a promising approach to regenerate bone tissue, and injectable biomaterials have shown potential for bone regeneration applications due to their ease of administration and ability to fill irregularly shaped defects. This study aims to develop and characterize an injectable composite material comprising biphasic bone substitutes (BBS) and crosslinked porcine collagen type I for bone regeneration applications. The collagen is crosslinked via a UVA-riboflavin crosslinking strategy and evaluated by testing the physicochemical properties, including the rheological behavior, dynamic storage modulus (G′) and loss modulus (G″), and in vitro degradation process. The results show that the crosslinked collagen (xCol) exhibits suitable physicochemical properties for injectability and improved viscoelasticity and degradation resistance. Furthermore, xCol is then combined with BBS in a predetermined ratio, obtaining the injectable composite material. The biocompatibility of the materials is evaluated in vitro by XTT and BrdU assays on fibroblasts and preosteoblasts. The results demonstrate that the composite material is biocompatible and supporting pre-osteoblasts proliferation. In conclusion, the injectable composite material BBS-xCol has promising physiochemical and biological properties for bone regeneration applications. Further studies are warranted to evaluate its efficacy in vivo and optimize its composition for clinical translation.     

DirectJ: Java APIs for optimized 2D graphics

The ever more widespread diffusion of Java interfaces and animations has highlighted the performance problems of the Java graphics environment. We have analysed the bottleneck and created a set of APIs that support direct access to platform specific hardware resources for graphics acceleration. We have also re‐implemented standard APIs in order to allow transparent direct access also by programs using standard JFC. The improvement in performance of about one order of magnitude encourages the utilization of Java for realizing fluid animations on large windows. Copyright © 2001 John Wiley & Sons, Ltd.