In this work, the chemical changes in calf thymus DNA samples were analyzed by X-ray photoelectron spectroscopy ͑XPS͒. The DNA samples were irradiated for over 5 h and spectra were taken repeatedly every 30 min. In this approach the X-ray beam both damages and probes the samples. In most cases, XPS spectra have complex shapes due to contributions of C, N, and O atoms bonded at several different sites. We show that from a comparative analysis of the modification in XPS line shapes of the C 1s, O 1s, N 1s, and P 2p peaks, one can gain insight into a number of reaction pathways leading to radiation damage to DNA.

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In the present study, pristine BiVO 4 , TiO 2 and BiVO 4 /TiO 2 core-shell heterostructured nanoparticles are prepared by hydrothermal methods and studied for structural, morphological, optical, photoelectrochemical water splitting and photocatalytic degradation of methylene blue as an organic pollutant. Both pristine BiVO 4 and TiO 2 exhibit poor PEC and PC performance under visible light illumination. However, an enhanced PEC and PC activity in BiVO 4 /TiO 2 core-shell heterostructure is observed due to high solar energy absorption and superior charge separation properties in core-shell nanoparticles. The photoelectrode prepared using BiVO 4 /TiO 2 core-shell nanoparticles exhibit a photocathode behavior and produced cathodic photocurrent, however, the pristine BiVO 4 and TiO 2 photoelectrodes act as photoanode and produced anodic photocurrent. This behavior of change in current direction is also observe in the Mott-Schottky analysis where the BiVO 4 /TiO 2 core-shell nanoparticles photoelectrode exhibits the positive slow showing p-type semiconducting behavior. The change in cathodic photoresponse in core-shell nanoparticles in comparison to anodic photoresponse of BiVO 4 and TiO 2 nanoparticles is explained in terms of the variations in the work function values. These results highlight the advantages of core-shell nanoparticle of suitable materials for photocatalytic and photoelectrochemical applications.

A new method of exposing silicon/semiconductor wafers to a mixture of radicals is described, in which these species are generated in an oxygen-rich gas discharge confined between a concentric pair of annular mesh electrodes surrounding the wafers. This approach allows the wafer surfaces to be treated without damage from the energetic ions, strong electric fields, and high UV fluxes associated with direct treatment by exposure to gas discharge plasmas. The process is compared with direct oxygen plasma activation for its latitude with respect to treatment duration, effect on wafer surface roughness and bond strength. Wider process latitude and reduced surface roughening are obtained for treatment by radicals compared with direct plasma exposure. Comparative analysis of treated and untreated silicon surfaces by X-ray photoelectron spectroscopy indicate that traces of fluorine present on the wafer surface before treatment are removed with great efficiency by the process.

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A technique to increase the conductivity of Spiro-OMeTAD using an easily scalable, nonthermal atmospheric pressure plasma jet (APPJ) is reported. An investigation of plasma functionalization demonstrated an enhancement in hole conductivity by over an order of magnitude from 9.4 × 10-7 S cm-1 for the pristine film to 1.15 × 10-5 S cm-1 for films after 5 minutes of plasma treatment. The conductivity value after plasma functionalization was comparable to that reported for 10 -25% Li-TFSI-doped Spiro-OMeTAD. The increase in conductivity was correlated with a reduction in phase value observed using electrostatic force microscopy. Kelvin probe force microscopy showed an increase in work function after plasma exposure corresponding to the p-type nature of the doping. X-ray photoelectron spectroscopy revealed surface oxidation of plasma-functionalized films, as well as variation in nitrogen chemistry, with the formation of a higher binding energy quaternary nitrogen tail. Oxidation of Spiro-OMeTAD was also confirmed by the appearance of the 500 nm absorption peak using UV-vis spectroscopy. The synergistic contribution of increase in charge density in Spiro-OMeTAD due to the energetic species in the plasma jet coupled with improvement in π-π stacking of the molecules is thought to underlie the conductivity enhancement. We also attribute the formation of quinoid structures with quaternary nitrogen +N=C to the enhancement in positive charge centres due to loss of methoxy groups during plasma-surface interaction. This work opens up the possibility of using an atmospheric pressure plasma jet as a simple and effective technique for doping and functionalizing Spiro-OMeTAD thin films to circumvent the detrimental issues associated with chemical dopants.

Team Engineering (first presented in autumn 2006) was the first course (module) at the Open University (OU) to use wikis and video-conferencing in combination to support the work of project teams. Teams of five students, working remotely from one another, tackle an engineering project over 32 weeks.The teams schedule regular meetings throughout the project and these are conducted using FlashMeeting, a lightweight video-conferencing system being developed by the OU's Knowledge Media Institute, KMi (http://flashmeeting.open.ac.uk). Unlike other systems, FlashMeeting requires no software installation. In addition, it not only archives the meetings but also provides detailed analysis of the proceedings.The teams are encouraged to use the wiki facility in the OU's virtual learning environment (VLE) for their collaborative report-writing. The collective work of the team is assessed through these reports. The performance of the individual is assessed through their reflective account of the project. The archiving facility in FlashMeeting has been of huge help in developing this. For the next presentation of the course a learning journal is to be added to the existing means of support.Feedback from tutors and students alike has been extremely positive, whilst recognising the limitations of the technologies in their current implementations. This paper gives an account of the students' achievements and offers an assessment of the pedagogic potential of using these media together. IntroductionTeam Engineering is the compulsory final course in programmes of study leading to the OU's Integrated Masters Degree in Engineering (MEng) and Postgraduate Diploma in Engineering qualifications. Entry to Team Engineering is only open to students who have completed all the other components of their programme, so this will always be the final course a student undertakes in order to complete their qualification. For both qualifications, these components include optional study selected from postgraduate courses in technology, computing, mathematics and science, plus a professional development planning course. In addition, the integrated MEng requires students to have completed an engineering honours degree not more than three years previously.

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