The ultrastructure of spruce kraft pulps studied by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS)

Surface properties of spruce (Picea abies) kraft pulps cooked for different times and further OD₀E₁D₁E₂D₂-bleached were investigated with atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). A rough correlation between the increasing relative amount of the fibrillar surface structure in AFM images and increasing O/C atomic ratio in XPS-spectra was found with proceeding delignification. At the end of cooking (120 min) only about 1/3 of the fibre surface consisted of cellulose. The detailed analysis of the relative peak areas of the different C1s components in the XPS-spectra indicated that the granules at the beginning of cooking at 170 °C consisted mainly of lignin and extractives. The analysis also showed that different steps of the bleaching sequence were quite specific in removing structural components. Furthermore, the lignin removal was shown not to result automatically in increased fraction of exposed cellulose surface, but could also lead in increased relative amount of surface extractives. Evidence for the high surface content of hemicelluloses for the D2-stage sample was observed. Hemicelluloses with both fibrillar and amorphous morphology were found to be present.     

The Relationship Between Online Pornography and the Sexual Objectification of Women: The Attenuating Role of Porn Literacy Education

Media literacy interventions partly aim at preventing undesirable media effects at a later point of time. However, longitudinal research on the interaction between media literacy education and media effects is lacking. In this longitudinal study among 1,947 13–25-year-olds, we started to address this lacuna by examining the potential of porn literacy education at schools to attenuate the longitudinal relationship between exposure to sexually explicit Internet material (SEIM) and views of women as sex objects. A two-way interaction effect emerged: The relationship between SEIM and sexist views became weaker, the more users had learned from porn literacy education. No gender or age differences occurred. This study thus provides some first evidence for the role of media education in reducing undesirable media effects.     

Optical properties of rotationally twinned InP nanowire heterostructures

We have developed a technique so that both transmission electron microscopy and microphotoluminescence can be performed on the same semiconductor nanowire over a large range of optical power, thus allowing us to directly correlate structural and optical properties of rotationally twinned zinc blende InP nanowires. We have constructed the energy band diagram of the resulting multiquantum well heterostructure and have performed detailed quantum mechanical calculations of the electron and hole wave functions. The excitation power dependent blue-shift of the photoluminescence can be explained in terms of the predicted staggered band alignment of the rotationally twinned zinc blende/wurzite InP heterostructure and of the concomitant diagonal transitions between localized electron and hole states responsible for radiative recombination. The ability of rotational twinning to introduce a heterostructure in a chemically homogeneous nanowire material and alter in a major way its optical properties opens new possibilities for band-structure engineering.     

Reproducible manufacturing of dye‐sensitized solar cells on a semi‐automated baseline

A fully operational baseline consisting of dedicated equipment to process nanocrystalline dye‐sensitized solar cell devices has been installed at ECN. This baseline focuses on the production of glass/glass devices with dimensions up to 10×10 cm². Present power conversion efficiencies of 6% obtained for cell areas of 2ċ5 cm² are successfully translated to 100 cm² devices with an active area of 68 cm² by application of identical cell components. The power conversion efficiency with respect to total area was 4%. Processing of a large number of devices in the baseline shows good results in terms of process reliability and yield. The overall yield for a series of 27 devices (10×10 cm²) was 96%, while 84% (22 of the remaining 26 devices) generated a cell efficiency within 7% deviation from the average value (4ċ3%). The reproducibility of the titanium dioxide (TiO₂) colloid synthesis has been investigated. The deviation from the average efficiency (4ċ9%) of three batches of colloid was at most 3ċ2%. These results prove that complete device manufacturing of nc‐DSC by a baseline process, starting with colloid synthesis is reproducible for surfaces up to 10×10 cm². Copyright © 2003 John Wiley & Sons, Ltd.     

Stability of X‐ray cellulose crystallite orientation parameters in native cotton with change of location and year of growth

In this article, data on cellulose crystallite orientation parameters measured in terms of the Hermans orientation factor, average angle of orientation (α_m), and 40, 50, and 75% X‐ray angles in respect to the same 13 cotton cultivars grown at different agroclimatic locations and in different crop years in India are presented and discussed. It was observed that whereas the average values of the X‐ray orientation parameters are different for different varieties they remain practically invariant within individual varieties with change of the location of growth. The orientation parameters, therefore, appear to be genetic in origin and independent of the agroclimatic conditions of growth. It is believed that these results can be suitably exploited by cotton breeders in evolving varieties with an increased strength of fibers. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 269–276, 1999     

Games to Create Awareness and Design Policies for Transboundary Cooperation in River Basins: Lessons from the Shariva Game of the Mekong River Commission

International river basins cover a vast majority of the land surface, international cooperation is therefore important for the proper management, and to assure equitable and effective use in the basins. Key elements to improve international cooperation are common understanding of the issues in the basin, understanding upstream-downstream impacts and sharing a common vision for the future. This article focuses on the role of games in international basin cooperation to create awareness and to support policy development. The paper analysed the effects of the game in creating awareness and upgrading knowledge amongst water and related professionals and in designing procedures for cooperation in transboundary river basins. This was analysed during the implementation of the game with 28 participants from the four Lower Mekong countries. The impact on creating awareness and upgrading knowledge was evaluated through the use of questionnaires and pre- and post evaluation questions and for the design of policies, a SWOT analysis was used to evaluate the usefulness of the policies and frameworks as well as to identify possible improvements to the framework. The game implementation proved to be an appropriate tool to provide a practical way for stakeholders to become acquainted with the administrative and technical tools available in the Lower Mekong Basin. Pre- and post test shows that participants gained substantial knowledge on transboundary cooperation and use of tools. The game was part of a longer training programme addressing all the issues, however, the participants gained additional knowledge and insight by playing the game, well above what they had learned during the earlier training workshops. Playing the game proved an important aspect in training and education of such complex systems. The study also shows the role games can play in policy analysis, in particular the way the game provided insight in the design of the policy and the development of procedures, and their function to review and update policies and procedures. A number of recommendations have been made to strengthen the role in both training and education as well as in design of procedures.