59,579 research outputs found
Comment: Demystifying Double Robustness: A Comparison of Alternative Strategies for Estimating a Population Mean from Incomplete Data
Comment on ``Demystifying Double Robustness: A Comparison of Alternative
Strategies for Estimating a Population Mean from Incomplete Data''
[arXiv:0804.2958]Comment: Published in at http://dx.doi.org/10.1214/07-STS227B the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Science, governance, and public participation: An analysis of decision making on genetic modification in Aotearoa/New Zealand
The acceptance of public participation in science and technology governance in liberal democratic contexts is evident in the institutionalization of a variety of mechanisms for participation in recent decades. Yet questions remain about the extent to which institutions have actually transformed their policy practice to embrace democratic governance of techno-scientific decision making. A critical discourse analysis of the response to public participation by the Environmental Risk Management Authority (ERMA), the key decision-making body on genetic modification in Aotearoa/New Zealand, in a specific case demonstrates that ERMA systematically marginalized concerns raised by the public about risk management, ethics, and ecological, economic, and cultural issues in order to give primacy to a positivist, technological worldview. Such delegitimization of public perspectives pre-empts the possibility of the democratic governance of science
Preparation of Nanocomposites from Styrene and Modified Graphite Oxides
Graphite oxide was prepared and modified with several ammonium salts and these modified graphite oxides were used to prepare nanocomposites with polystyrene by in situ polymerization of styrene monomer and by melt blending with polystyrene. Nanocomposites were characterized by X-ray diffraction, cone calorimetry, thermogravimetric analysis and the evaluation of mechanical properties. Nanocomposites are formed by in situ polymerization but not by melt blending; the graphite oxide undergoes thermal degradation at the temperature of melt blending so nanocomposite formation would be unlikely. Mechanical properties of the melt blended nanocomposites are improved relative to the virgin polystyrene while those prepared by in situ polymerization are decreased, except in the case of Young\u27s Modulus, where melt blended and in situ polymerized materials show similar results
Polybutadiene Cross-Linked With Various Diols – Effect On Thermal Stability
The relationship between cross-linking and thermal stability as related to polybutadiene is the focus of current research. Cross-linked polybutadienes have been prepared using various diols as the cross-linking agent. Cross-linked polymers have been characterized by gel content, swelling ratios, infrared spectroscopy, and thermal analysis. These polymers are not highly cross-linked, as seen by gel content and swelling ratios, and cross-linking does not have a large effect on the onset temperature of the degradation. Nonetheless, extensive formation of a non-volatile residue occurs
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