Static and dynamic characterization of pull-in protected CMOS compatible poly-SiGe grating light valves

status: publishe

The challenges of urban ageing:Making cities age-friendly in Europe

Urban ageing is an emerging domain that deals with the population of older people living in cities. The ageing of society is a positive yet challenging phenomenon, as population ageing and urbanisation are the culmination of successful human development. One could argue whether the city environment is an ideal place for people to grow old and live at an old age compared to rural areas. This viewpoint article explores and describes the challenges that are encountered when making cities age-friendly in Europe. Such challenges include the creation of inclusive neighbourhoods and the implementation of technology for ageing-in-place. Examples from projects in two age-friendly cities in The Netherlands (The Hague) and Poland (Cracow) are shown to illustrate the potential of making cities more tuned to the needs of older people and identify important challenges for the next couple of years. Overall, the global ageing of urban populations calls for more age-friendly approaches to be implemented in our cities. It is a challenge to prepare for these developments in such a way that both current and future generations of older people can benefit from age-friendly strategies

Properties of Dust Grains in Planetary Nebulae -- I. The Ionized Region of NGC 6445

In this paper we study new infrared spectra of the evolved planetary nebula NGC 6445 obtained with ISO. These data show that the thermal emission from the grains is very cool and has a low flux compared to H beta. A model of the ionized region is constructed, using the photo-ionization code CLOUDY 90.05. Based on this model, we show from depletions in the gas phase elements that little grain destruction can have occurred in the ionized region of NGC 6445. We also argue that dust-gas separation in the nebula is not plausible. The most likely conclusion is that grains are residing inside the ionized region of NGC 6445 and that the low temperature and flux of the grain emission are caused by the low luminosity of the central star and the low optical depth of the grains. This implies that the bulk of the silicon-bearing grains in this nebula were able to survive exposure to hard UV photons for at least several thousands of years, contradicting previously published results. A comparison between optical and infrared diagnostic line ratios gives a marginal indication for the presence of a t^2-effect in the nebula. However, the evidence is not convincing and other explanations for the discrepancy are also plausible. The off-source spectrum taken with ISO-LWS clearly shows the presence of a warm cirrus component with a temperature of 24 K as well as a very cold component with a temperature of 7 K. Since our observation encompasses only a small region of the sky, it is not clear how extended the 7 K component is and whether it contributed significantly to the FIRAS spectrum taken by COBE. Because our line of sight is in the galactic plane, the very cold component could be a starless core.Comment: 36 pages, 8 tables, 7 figures, accepted for publication in Ap

Current-induced spin-wave excitations in a single ferromagnetic layer

A new current induced spin-torque transfer effect has been observed in a single ferromagnetic layer without resorting to multilayers. At a specific current density of one polarity injected from a point contact, abrupt resistance changes due to current-induced spin wave excitations have been observed. The critical current at the onset of spin-wave excitations depends linearly on the external field applied perpendicular to the layer. The observed effect is due to current-driven heterogeneity in an otherwise uniform ferromagnetic layer.Comment: 12 pages, 4 figure

Policy search with high-dimensional context variables

Direct contextual policy search methods learn to improve policy parameters and simultaneously generalize these parameters to different context or task variables. However, learning from high-dimensional context variables, such as camera images, is still a prominent problem in many real-world tasks. A naive application of unsupervised dimensionality reduction methods to the context variables, such as principal component analysis, is insufficient as task-relevant input may be ignored. In this paper, we propose a contextual policy search method in the model-based relative entropy stochastic search framework with integrated dimensionality reduction. We learn a model of the reward that is locally quadratic in both the policy parameters and the context variables. Furthermore, we perform supervised linear dimensionality reduction on the context variables by nuclear norm regularization. The experimental results show that the proposed method outperforms naive dimensionality reduction via principal component analysis and a state-of-the-art contextual policy search method

The Real-Time Evolution of Sakurai's Star (V4334 Sgr) and other (V)LTP Objects

We report on the progress of our on-going campaign to monitor the evolution of the VLTP objects V4334 Sgr and V605 Aql, as well as the suspected (V)LTP object CK Vul. V4334 Sgr does not show signs of increased ionization compared to our previous observations in 2004. We obtained the first radio detection of V605 Aql, indicating a strong increase in radio flux since 1987. We also present the first radio detection of CK Vul and discuss the expansion of the material ejected during the 1670 event.Comment: 4 pages, 2 figures in eps format, IAU symp. 234: `Planetary Nebulae in our Galaxy and Beyond', eds. M. J. Barlow & R. H. Mende

Cost-benefit analysis of abatement measures for nutrient emission from agriculture

In intensive animal husbandry areas surface water N and P concentrations often remain too high. The Water Framework Directive calls for additional nutrient emission abatement measures. Therefore, costs and benefits for possible agricultural measures in Flanders were first analysed in terms of soil balance surplus. Finally, abatement measures for agriculture, households and industry were set off against each other and ranked according to their cost-efficiency by the Environmental Costing Model. Increased dairy cattle efficiency, winter cover crops and increased pig feed efficiency turn out very cost efficient. Other agricultural measures are less cost efficient than for instance collective treatment for households and industry.nitrogen and phosphorus abatement, surface water, cost efficiency, Environmental Economics and Policy, Livestock Production/Industries,