Methacrylated Calix[6]arenes as Low Shrinking Additives for Dental Restorative Composites

p‐tert‐Butylcalix[6]arene was acylated with different carboxylic acid anhydrides to improve their solubility in dimethacrylate cross‐linkers. An esterification of p‐tert‐butylcalix[6]arene 1 with octanoic anhydride followed by methacrylation of the residual hydroxy groups with methacrylic anhydride resulted mainly in the formation of a pentaoctanoatemonomethacrylate 2a . In the radical polymerization of methyl methacrylate the inhibition effect of residual hydroxy groups in 2a was evaluated. Dimethacrylate containing composites based on a monomer matrix of cross‐linking dimethacrylates and 0–30 wt.% of 2a were prepared. The addition of 2a resulted in a significant decrease of the polymerization shrinkage, whereas the modulus of elasticity of the visible light cured composites was not affected.

     

Reinventing R&D in an open innovation ecosystem

Today, the idea that random collisions and interactions offer solutions and business opportunities is no longer acceptable. Instead, partnerships and alignments, both downstream and upstream, are paramount for cross-fertilization and synergy. To survive, and thrive, in today's world of global innovation, alliances based on compatible differences must be sought. Innovation Partnerships and the Sharing-is-Winning model represent a paradigm shift toward accelerating co-development of sustainable innovation, with alignment of the entire value chain with consumer-centric innovations being one of its main pillars. It includes 3 levels of typical joint development: universities, research institutes, and centers; start-ups and individual inventors; a select number of key strategic suppliers. Reinventing R&D in an open innovation ecosystem and increasing success rates in an increasingly competitive marketplace require implementing significant steps--both perceived and tangible. Specific recommendations are provided for 10 major identified topics: leadership, strategy, the consumer, the value chain, internal experts and championship, metrics, IP, culture, academia, and passion. The Sharing-is-Winning model extends the scope of open innovation to sustainable and enhanced processes of co-innovation.     

Optimal climate protection strategies for space heating: The case of Austria

The debate over the costs of climate protection policies still focuses on the question of whether strategies to significantly reduce greenhouse gas emissions at zero or negative net cost (‘no regrets’ strategies) can be found. This article describes a carbon dioxide (CO₂) reduction strategy for space and water heating in Austria relying on net present value analyses of 43 climate protection measures. The cost-benefit analyses include investment costs, the savings from energy conservation, the administrative costs of policy instruments and estimates of the external costs. An efficient CO₂ reduction strategy was developed on the basis of energy supply curves which were adapted so that interactions between the CO₂ reduction technologies could be considered. A cost-efficient CO₂ reduction strategy could lower the CO₂ emissions for the provision of space and water heating in Austria by up to 2.7% per year relative to the official ‘business as usual’ scenario.     

Efficiency model for photovoltaic modules and demonstration of its application to energy yield estimation

A new method has been proposed [W. Durisch, K.H. Lam, J. Close, Behaviour of a copper indium gallium diselenide module under real operating conditions, in: Proceedings of the World Renewable Energy Congress VII, Pergamon Press, Oxford, Elsevier, Amsterdam, 2002, ISBN 0-08-044079-7] for the calculation of the annual yield of photovoltaic (PV) modules at selected sites, using site-specific meteorological data. These yields are indispensable for calculating the expected cost of electricity generation for different modules, thus allowing the type of module to be selected with the highest yield-to-cost ratio for a specific installation site. The efficiency model developed and used for calculating the yields takes three independent variables into account: cell temperature, solar irradiance and relative air mass. Open parameters of the model for a selected module are obtained from current/voltage (I/V) characteristics, measured outdoors at Paul Scherrer Institute's test facility under real operating conditions. From the model, cell and module efficiencies can be calculated under all relevant operating conditions. Yield calculations were performed for five commercial modules (BP Solar BP 585 F, Kyocera LA361K54S, Uni-Solar UPM-US-30, Siemens CIS ST40 and Wuerth WS11003) for a sunny site in Jordan (Al Qawairah) for which reliable measured meteorological data are available. These represent mono-crystalline, poly-crystalline and amorphous silicon as well as with copper–indium-diselenide, CuInSe₂ PV modules. The annual yield for these modules will be presented and discussed.     

Faces versus patterns: Exploring aesthetic reactions using facial EMG.

We used facial EMG to examine reactions to the attractiveness of natural (faces) and artificial (abstract patterns) stimuli under long and short presentation durations. Attractive stimuli produced strong activations of the M. zygomaticus major muscle, indicating positive affective reactions; and unattractive stimuli produced strong activations of the M. corrugator supercili muscle, indicating negative affective reactions. Fluency effects, indicated by stronger activations of the M. zygomaticus major under the longer presentation duration were, however, only found for the abstract patterns. Moreover, the abstract patterns also were associated with more consistent activations over time than the faces, suggesting differences in the processes underlying the evaluation of faces and patterns. We discuss these results in terms of differences in appraisal processes between the two classes of stimuli—the greater biological, social, and sociosexual significance of faces trigger more complex appraisals than the abstract patterns. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Calcite Reinforced Silica–Silica Joints in the Biocomposite Skeleton of Deep‐Sea Glass Sponges

The hierarchically structured glass sponge Caulophacus species uses the first known example of a silica and calcite biocomposite to join the spicules of its skeleton together. In the stalk and body skeleton of this poorly known deep‐sea glass sponge siliceous spicules are modified by the addition of conical calcite seeds, which then form the basis for further silica secretion to form a spinose region. Spinose regions on adjacent spicules are then joined by siliceous crosslinks, leading to unusually strong cross‐spicule linkages. In addition to the biomaterials implications it is now clear, from this first record of a biomineral other than silica, that the hexactinellid sponges are capable of synthesizing calcite, the ancestral skeletal material. We propose that, while the low concentrations of calcium in deep sea waters drove the evolution of silica skeletons, the brittleness of silica has led to retention of the more resilient calcite in very low concentrations at the skeletal joints.     

Quantitative characterization of xenon bubbles in silicon: Correlation of bubble size with the damage generated during implantation

Making use of Fresnel fringe contrast under different focusing conditions in transmission electron microscopy (TEM), we present a detailed evaluation of the depth dependent size distribution of gas bubbles contained in a stationary profile of 40 keV Xe implanted in Si. Voids generated during sample preparation by ion milling were also characterized carefully. The largest bubbles, with mean and maximum sizes of 5 and 7 nm, respectively, were observed at depths <22 nm. However, the first 2 nm of the sample did not contain any bubbles. Towards the end of range the bubble size decreased rapidly. No bubbles were found beyond 45 nm (the minimum size of detectable bubbles was estimated to be about 1.8 nm). Some observations suggest that the bubbles were over-pressurized. The derived data could be converted to a depth dependence of the Xe concentration contained in bubbles, n_Xe,b. Comparison with the previously reported depth distribution of Xe measured by Rutherford backscattering spectrometry (RBS), n_Xe,b turned out to be depth dependent, with a maximum of ∼28% in the region of maximum bubble size. n_Xe,b is shown to correlate closely with the damage density generated during Xe implantation. The findings lead to a model of bubble formation which involves the idea that the redistribution and transport processes initiated by ion impact take place mostly during the lifetime of the collision cascade.     

Analysis of dynamic matching networks for the ICRF system at ASDEX Upgrade

The ICRF (Ion Cyclotron Range of Frequencies) system, used to heat the plasma of ASDEX Upgrade, consists of RF generators, 3 dB hybrids, coaxial transmission lines, matching networks and inductive loop antennas. The maximum power achievable by the generator strongly depends on the amplitude and phase of the reflection coefficient. Hence, matching of the antenna input impedance to the generator output impedance is essential for the ICRF heating system. The coupling between the ICRF antennas and the plasma is subject to relatively fast variations (few ms). The changes are caused by the modification of plasma edge conditions, such as L–H mode transitions, gas puffing or ELMs (Edge Localized Modes). These variations change the impedance of the ICRF antennas. For optimal operation of the ICRF system, a continuous, and fast matching is therefore preferable. A MATLAB^® based simulation tool has been developed to analyse matching networks for the ICRF system at ASDEX Upgrade. The program is highly flexible, and can solve the matching calculations for different conditions and configurations of the system. The results are presented in a Smith chart.     

Solution of FE‐BE coupled eigenvalue problems for the prediction of the vibro‐acoustic behavior of ship‐like structures

To predict the vibro‐acoustic behavior of structures, both a structural problem and an acoustic problem have to be solved. For thin structures immersed in water, a strong interaction between the structural domain and fluid domain occurs. This significantly alters the resonance frequencies. In this work, the structure is modeled by the finite element method. The exterior acoustic problem is solved by a fast boundary element method employing hierarchical matrices. An FE‐BE formulation is presented, which allows the solution of the coupled eigenvalue problem and thus the prediction of the coupled eigenfrequencies and mode shapes. It is based on a Schur complement formulation of the FE‐BE system yielding a generalized eigenvalue problem. A Krylov–Schur solver is applied for its efficient solution. Hereby, the compressibility of the fluid is neglected. The coupled eigensolution is then used for a model reduction strategy allowing fast frequency sweep calculations. The efficiency of the proposed formulations is investigated with respect to memory consumption, accuracy, and computation time. Copyright © 2011 John Wiley & Sons, Ltd.     

Workplace monitoring of mixed neutron-photon radiation fields and its contribution to external dosimetry

Workplace monitoring is a common procedure for determining measures for routine radiation protection in a particular working environment. For mixed radiation fields consisting of neutrons and photons, it is of increased importance because it contributes to the improved accuracy of individual monitoring. An example is the determination of field-specific correction factors, which can be applied to the readings of personal dosemeters. This paper explains the general problems associated with individual dosimetry of neutron radiation, and describes the various options for workplace monitoring. These options cover a range from the elaborate field characterisation using transport calculations or spectrometers to the simpler approach using area monitors. Examples are given for workplaces in nuclear industry, at particle accelerators and at flight altitudes.