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The presence of pathogens and other stresses at germination and seedling stages affect the successful establishment of crops. The use of non-thermal plasma is a new approach to reduce such stresses. Plasma can interact with seeds and change their surface characteristics by etching, introducing functional groups and coating with exotic materials. Emerging evidence indicate that plasma treatment of seeds can enhance germination and seedling growth in crops by removal of microbial layers, changes in water uptake and other changes. Here, we review the status of research and show the potential role that plasma technology can play in addressing the challenges in food production. Major progress is possible by plasma treatments at or near atmospheric pressure where batch processing of large seed samples is possible.

Abstract:Unique macrostructures known as spun carbon-nanotube fibers (CNT yarns) can be manufactured from vertically aligned forests of multi-walled carbon nanotubes (MWCNTs). These yarns behave as semiconductors with room-temperature conductivities of about 5x10 2 S cm -1 . Their potential use as, for example, microelectrodes in medical implants, wires in microelectronics, or lightweight conductors in the aviation industry has hitherto been hampered by their insufficient electrical conductivity. In this Full Paper, the synthesis of metal-CNT composite yarns, which combine the unique properties of CNT yarns and nanocrystalline metals to obtain a new class of materials with enhanced electrical conductivity, is presented. The synthesis is achieved using a new technique, self-fuelled electro deposition (SFED), which combines a metal reducing agent and an external circuit for transfer of electrons to the CNT surface, where the deposition of metal nano-particles takes place. In particular, the Cu-CNT and Au-CNT composite yarns prepared by this method have metallike electrical conductivities (2-3 x 10 5 S cm -1 ) and are mechanically robust against stringent tape tests. However, the tensile strengths of the composite yarns are 30-50% smaller than that of the unmodified CNT yarn. The SFED technique described here can also be used as a convenient means for the deposition of metal nano-particles on solid electrode supports, such as conducting glass or carbon black, for catalytic applications.

There is evidence that the halogen loading of the atmosphere has peaked and stratospheric ozone levels are expected to recover to pre‐1980 levels this century. However, N2O concentrations in the atmosphere are increasing, resulting in increasing levels of NOx in the stratosphere. In addition, the growth rate in the atmospheric methane burden has declined in recent years, leading to the suggestion that methane emissions have stabilized. A 2‐D chemical transport model is used to calculate stratospheric ozone from 2000 to 2100 for a range of IPCC scenarios. The model predicts that mid‐latitude stratospheric ozone will recover only partially towards pre‐1980 levels over the next 50 years, but will then decline, largely due to increases in stratospheric NOx. If greenhouse gas mitigation strategies result in lower future methane levels, mid‐latitude stratospheric ozone levels in 2100 are predicted to be lower than current values, particularly in late summer and autumn.

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Amorphous TiO 2 thin films were synthesized using a pulsed direct current plasma deposition technique. The films were prepared in the discharges of Ar, Ar + O 2 , and Ar + N 2 . The original and annealed samples were characterized using X-ray diffraction, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy, ultraviolet and visible spectroscopy (UV-vis), and electrochemistry. The presence of oxygen was found to be essential in the annealing medium for the formation of polycrystalline films. By optimizing the experimental conditions, we obtained TiO 2 films that showed 80% incident photon conversion efficiency for splitting of water near 300 nm. Films containing up to 12 atom % N were obtained when mixtures of Ar and N 2 were used as the plasma source gas. Although there is evidence for the presence of Ti-N bonds in the amorphous film, the annealing in the presence of oxygen to obtain polycrystalline films led to decomposition of these bonds. The resulting polycrystalline films contained 1-2 atom % of N (XPS peak at 399.5 ( 0.5 eV) and showed visible light absorption. However, in contrast to recent reports in the literature for powdered materials with similar XPS and UV-vis characteristics oxidation of water or formic acid could not be achieved using these films under visible light illumination. There is evidence that the holes generated in the occupied N 2p midgap levels are recombining efficiently at the carbon-impurity sites.

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