Set-up and characterization of a humidity sensor realized in LTCC-technology

A new type of integrated temperature and humidity sensor applying LTCC-technology has been developed and characterized. In this approach, sensing elements are implemented using heated metal resistors (Pt-elements), where one is exposed to the humid environment that causes the sensor element to cool down with increased humidity, while the other one is sealed from the environment. Sensor design is based on FEA (Finite Element Analyses) where the critical design parameters have been analyzed with regard to the performance characteristic of the device. The set-up of sensor element will be shown and the functional capability will be demonstrated by experimental results.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Results from NA61/SHINE

In this paper we summarize recent results from NA61/SHINE relevant for heavy ion physics, neutrino oscillations and the interpretation of air showers induced by ultra-high energy cosmic rays.Comment: 7 pages, Talk given at the International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2012), Berlin, Germany, to appear in EPJ web of Con

Legitimating inaction : differing identity constructions of the Scots language.

The Scots language plays a key role in the political and cultural landscape of contemporary Scotland. From a discourse-historical perspective, this article explores how language ideologies about the Scots language are realized linguistically in a so-called ‘languages strategy’ drafted by the Scottish Executive, and in focus groups consisting of Scottish people. This article shows that although the decline of Scots is said to be a ‘tragedy’, focus group participants seem to reject the notion of Scots as a viable, contemporary language that can be used across a wide range of registers. The policy document also seems to construct Scots in very positive terms, but is shown to be unhelpful or potentially even damaging in the process of changing public attitudes to Scots

Unjamming of Granular Packings due to Local Perturbations: Stability and Decay of Displacements

We study the mechanical response generated by local deformations in jammed packings of rigid disks. Based on discrete element simulations we determine the critical force of the local perturbation that is needed to break the mechanical equilibrium and examine the generated displacement field. Displacements decay as a power law of the distance from the perturbation point. The decay exponent and the critical force exhibit nontrivial dependence on the friction: Both quantities are nonmonotonic and have a sharp maximum at the friction coefficient 0.1. We find that the mechanical response properties are closely related to the problem of force-indeterminacy where similar nonmonotonic behavior was observed previously. We establish direct connection between the critical force and the ensemble of static force networks.Comment: 4 pages, 4 figure

Cation Alloying as a Pathway to Reproducible olution Based Preparation of Efficient Metal Halide Perovskites Solar Cells with Increased Stability

With a certain amount of serendipity, research on dye sensitized solar cells led to the discovery of metal halide perovskite semiconductors as a solar energy conversion material1,2 that has inspired world wide research activities leading to efficiency increases from about 10 in 20123,4 to now 22 .5 8 Apart from their use as a single junction solar cell technology, metal halide perovskites can be processed as an add on layer onto other solar cells to realize efficient and low cost tandem architectures. The perovskite band gap can be tuned continuously from 1.1 to 3.0 eV by chemical engineering which makes them particularly relevant for multi junction devices.9 12 Experimental demonstrations of efficient tandem devices comprising metal halide perovskites as one13 15 or both10,16 components in a tandem stack highlight the potential for scalable and low cost multi junction devices17 with efficiencies approaching 30 is considered feasible.18,12,19,20 To reach this performance in a perovskite silicon tandem, the ideal band gap of the absorber material in top device should be about 1.7 eV18,12,21 sine silicon has a band gap of 1.1 eV .11,22,23 In this review, we dedicate section I to the discussion of the chemical tunability of metal halide perovskite with a particular focus on absorber materials with absorption onsets around 1.6 eV. Section II reflects on the benefit and role of including cesium Cs highlighting the work by Saliba et al.5,6 as this approach demonstrates a reliable pathway to obtain efficient solution processed metal halide perovskite absorbers with high reproducibility and extended operational device stability. Section III focuses on the state of the art of perovskite photovoltaics as a function of the absorption onset of the absorber layer highlighting materials with band gaps between 1.6 eV 1.75 eV as these are of great importance to the development of efficient tandem solar cells.12,18 20 In the conclusion section IV, we reflect on more general trends in metal halide alloys partially iscussed elsewhere23 highlighting cation alloying as an approach to obtain highly efficient devices in the band gap range between 1.6 and 1.7 eV. The data shown and discussed here is dominantly based on three of our recent publications and the interested reader is kindly referred to Unger et al.23 and Saliba et al.5,6 for more in depth discussions and experimental details

Extent of force indeterminacy in packings of frictional rigid disks

Static packings of frictional rigid particles are investigated by means of discrete element simulations. We explore the ensemble of allowed force realizations in the space of contact forces for a given packing structure. We estimate the extent of force indeterminacy with different methods. The indeterminacy exhibits a nonmonotonic dependence on the interparticle friction coefficient. We verify directly that larger force-indeterminacy is accompanied by a more robust behavior against local perturbations. We also investigate the local indeterminacy of individual contact forces. The probability distribution of local indeterminacy changes its shape depending on friction. We find that local indeterminacy tends to be larger on force chains for intermediate friction. This correlation disappears in the large friction limit.Comment: 5 pages, 6 figure

Molecular dynamics of folding of secondary structures in Go-type models of proteins

We consider six different secondary structures of proteins and construct two types of Go-type off-lattice models: with the steric constraints and without. The basic aminoacid-aminoacid potential is Lennard Jones for the native contacts and a soft repulsion for the non-native contacts. The interactions are chosen to make the target secondary structure be the native state of the system. We provide a thorough equilibrium and kinetic characterization of the sequences through the molecular dynamics simulations with the Langevin noise. Models with the steric constraints are found to be better folders and to be more stable, especially in the case of the $\beta$-structures. Phononic spectra for vibrations around the native states have low frequency gaps that correlate with the thermodynamic stability. Folding of the secondary structures proceeds through a well defined sequence of events. For instance, $\alpha$-helices fold from the ends first. The closer to the native state, the faster establishment of the contacts. Increasing the system size deteriorates the folding characteristics. We study the folding times as a function of viscous friction and find a regime of moderate friction with the linear dependence. We also consider folding when one end of a structure is pinned which imitates instantaneous conditions when a protein is being synthesized. We find that, under such circumstances, folding of helices is faster and of the $\beta$-sequences slower.Comment: REVTeX, 14 pages, EPS figures included, JCP in pres

Human capital and entrepreneurial success : a meta-analytical review

The study meta-analytically integrates results from three decades of human capital research in entrepreneurship. Based on 70 independent samples (N = 24,733), we found a significant but small relationship between human capital and success (r(c) = .098). We examined theoretically derived moderators of this relationship referring to conceptualizations of human capital, to context, and to measurement of success. The relationship was higher for outcomes of human capital investments (knowledge/skills) than for human capital investments (education/experience), for human capital with high task-relatedness compared to low task-relatedness, for young businesses compared to old businesses, and for the dependent variable size compared to growth or profitability. Findings are relevant for practitioners (lenders, policy makers, educators) and for future research. Our findings show that future research should pursue moderator approaches to study the effects of human capital on success. Further, human capital is most important if it is task-related and if it consists of outcomes of human capital investments rather than human capital investments; this suggests that research should overcome a static view of human capital and should rather investigate the processes of learning, knowledge acquisition, and the transfer of knowledge to entrepreneurial tasks