Mechanical behavior of thermal barrier coatings for gas turbine blades

Plasma-sprayed thermal barrier coatings (TBCs) will enable turbine components to operate at higher temperatures and lower cooling gas flow rates; thereby improving their efficiency. Future developments are limited by precise knowledge of the material properties and failure mechanisms of the coating system. Details of this nature are needed for realistic modeling of the coating system which will, in turn, promote advancements in coating technology. Complementary experiments and analytical modeling which were undertaken in order to define and measure the important failure processes for plasma-sprayed coatings are presented. The experimental portion includes two different tests which were developed to measure coating properties. These are termed tensile adhesion and acoustic emission tests. The analytical modeling section details a finite element method which was used to calculate the stress distribution in the coating system. Some preliminary results are presented

General cost analysis for scholarly communication in Germany : results of the "Houghton Report" for Germany

Management Summary: Conducted within the project “Economic Implications of New Models for Information Supply for Science and Research in Germany”, the Houghton Report for Germany provides a general cost and benefit analysis for scientific communication in Germany comparing different scenarios according to their specific costs and explicitly including the German National License Program (NLP). Basing on the scholarly lifecycle process model outlined by Björk (2007), the study compared the following scenarios according to their accounted costs: - Traditional subscription publishing, - Open access publishing (Gold Open Access; refers primarily to journal publishing where access is free of charge to readers, while the authors or funding organisations pay for publication) - Open Access self-archiving (authors deposit their work in online open access institutional or subject-based repositories, making it freely available to anyone with Internet access; further divided into (i) CGreen Open Access’ self-archiving operating in parallel with subscription publishing; and (ii) the ‘overlay services’ model in which self-archiving provides the foundation for overlay services (e.g. peer review, branding and quality control services)) - the NLP. Within all scenarios, five core activity elements (Fund research and research communication; perform research and communicate the results; publish scientific and scholarly works; facilitate dissemination, retrieval and preservation; study publications and apply the knowledge) were modeled and priced with all their including activities. Modelling the impacts of an increase in accessibility and efficiency resulting from more open access on returns to R&D over a 20 year period and then comparing costs and benefits, we find that the benefits of open access publishing models are likely to substantially outweigh the costs and, while smaller, the benefits of the German NLP also exceed the costs. This analysis of the potential benefits of more open access to research findings suggests that different publishing models can make a material difference to the benefits realised, as well as the costs faced. It seems likely that more Open Access would have substantial net benefits in the longer term and, while net benefits may be lower during a transitional period, they are likely to be positive for both ‘author-pays’ Open Access publishing and the ‘over-lay journals’ alternatives (‘Gold Open Access’), and for parallel subscription publishing and self-archiving (‘Green Open Access’). The NLP returns substantial benefits and savings at a modest cost, returning one of the highest benefit/cost ratios available from unilateral national policies during a transitional period (second to that of ‘Green Open Access’ self-archiving). Whether ‘Green Open Access’ self-archiving in parallel with subscriptions is a sustainable model over the longer term is debateable, and what impact the NLP may have on the take up of Open Access alternatives is also an important consideration. So too is the potential for developments in Open Access or other scholarly publishing business models to significantly change the relative cost-benefit of the NLP over time. The results are comparable to those of previous studies from the UK and Netherlands. Green Open Access in parallel with the traditional model yields the best benefits/cost ratio. Beside its benefits/cost ratio, the meaningfulness of the NLP is given by its enforceability. The true costs of toll access publishing (beside the buyback” of information) is the prohibition of access to research and knowledge for society

Opportunities for Improving the Drug Development Process: Results from a Survey of Industry and the FDA

In the United States, the Food and Drug Administration (FDA) agency is responsible for regulating the safety and efficacy of biopharmaceutical drug products. Furthermore, the FDA is tasked with speeding new medical innovations to market. These two missions create an inherent tension within the agency and between the agency and key stakeholders. Oftentimes, communications and interactions between regulated companies and the FDA suffer. The focus of this research is on the interactions between the FDA and the biopharmaceutical companies that perform drug R&D. To assess the current issues and state of communication and interaction between the FDA and industry, we carried out a survey of industry leadership in R&D and regulatory positions as well as senior leadership at the FDA who have responsibility for drug evaluation and oversight. Based on forty-nine industry and eight FDA interviews we conducted, we found that industry seeks additional structured and informal interactions with the FDA, especially during Phase II of development. Overall, industry placed greater value on additional communication than did the FDA. Furthermore, industry interviewees indicated that they were willing to pay PDUFA-like fees during clinical development to ensure that the FDA could hire additional, well-qualified staff to assist with protocol reviews and decision-making. Based on our survey and discussions, we uncovered several thematic opportunities to improve interactions between the FDA and industry and to reduce clinical development times: 1) develop metrics and goals at the FDA for clinical development times in exchange for PDUFA like fees; 2) establish an oversight board consisting of industry, agency officials, and premier external scientists (possibly at NIH or CDC) to evaluate and audit retrospectively completed and terminated drug projects; and 3) construct a knowledge database that can simultaneously protect proprietary data while allowing sponsor companies to understand safety issues and problems of previously developed/failed drug programs. While profound scientific and medical challenges face the FDA and industry, the first step to reducing development times and associated costs and facilitating innovation is to provide an efficient regulatory process that reduces unnecessary uncertainty and delays due to lack of communication and interaction.

Atom Transfer and Single-Adatom Contacts

The point contact of a tunnel tip approaching towards Ag(111) and Cu(111) surfaces is investigated with a low temperature scanning tunneling microscope. A sharp jump-to-contact, random in nature, is observed in the conductance. After point contact, the tip-apex atom is transferred to the surface, indicating that a one-atom contact is formed during the approach. In sharp contrast, the conductance over single silver and copper adatoms exhibits a smooth and reproducible transition from tunneling to contact regime. Numerical simulations show that this is a consequence of the additional dipolar bonding between the homoepitaxial adatom and the surface atoms.Comment: 4 pages, 4 figure

"QGP Signatures" Revisited

We revisit the graphic table of QCD signatures in our 1996 Annual Reviews article "The Search for the Quark-Gluon Plasma" and assess the progress that has been made since its publication towards providing quantitative evidence for the formation of a quark-gluon plasma in relativistic heavy-ion collisions and its characteristic properties.Comment: 42 pages, 47 figure