A case of reversible deafness in cystic arachnoiditis (author's transl)

A patient studied preoperatively by a neuro-otological test battery showed signs of an extensive cerebellopontine angle tumour. During the operation dense fibrotic tissue was found extending from the choroid plexus to the right acoustic nerve, which was freed and thus decompressed. Postoperatively, low frequency hearing improved markedly in the right ear. In contrast to the well-known documented cases of successful decompression of the optic nerve it has not been possible up to now to achieve a successful outcome in similar procedures on the acoustic nerve. In the described case the fibrotic lesion had obviously just caused reversible damage to the myelin sheaths of the eighth nerve, which can be interpreted as "neurapraxia" (Seddon, 1943). Further investigations in regard to the systematic elucidation of possibly reversible damage to the acoustic nerve are currently being performed at the IInd ENT department of Vienna University.     

Characterization of tribo-layers on self-lubricating plasma-assisted chemical-vapor-deposited TiN coatings

Recently, several new solid lubricants and modern lubrication concepts have been developed to achieve lower friction and wear and thus longer lifetime in severe tribological applications. The aim of this study is to characterize tribo-layers formed during ball-on-disc testing on low-friction, Cl-containing TiN coatings deposited by plasma assisted chemical vapor deposition and to clarify their formation mechanism. Characterization of the transfer layers was done by optical microscopy, optical profilometry, Raman spectroscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy. Differential scanning calorimetry was used to provide information on the chlorine-influenced chemical reactions of the coatings in ambient air. Iron oxide layers of a thickness in the nm-range have been found on low-chlorine containing TiN coatings (<3 at.% Cl) showing friction coefficients of approximately 0.8, whereas on TiN coatings with higher chlorine contents (>3 at.% Cl) rutile layers were preferably formed, resulting in friction coefficients below 0.2. This self-lubrication mechanism can be explained by the in-situ formation of easy-shearable titanium oxides in the contact zone in the presence of humidity and oxygen.     

Modeling Firm and Market Dynamics: A Flexible Model Reproducing Existing Stylized Facts on Firm Growth

This paper presents a model of firm and market dynamics that is able to reproduce the empirically observed patterns on firm growth and its statistical characteristics. It goes beyond the existing firm models by reproducing all stylized facts established in the literature. Furthermore, the model is flexible in the sense that various parameter settings are identified that reproduce the stylized facts. We identify and discuss different ranges of the model’s parameters that allow for adapting the model to certain industries and life-cycle stages.     

Power to the people or regulatory ratcheting? Explaining the success (or failure) of attempts to site commercial US nuclear power plants: 1954–1996

Between 1954 and 1996, more than 200 nuclear power projects were publicly announced in the USA. Barely half of these projects were completed and generated power commercially. Existing research has highlighted a number of potential explanations for the varying siting outcomes of these projects, including contentious political protests, socioeconomic and political conditions within potential host communities, regulatory changes (‘ratcheting’), and cost overruns. However, questions remain about which of these factors, if any, had an impact on these outcomes. This article uses a new data set of 228 host communities where siting was attempted to illuminate the factors that led projects towards either completion or cancelation. Controlling for factors highlighted by past studies, we find that regulatory, site‐ and reactor‐specific factors predict the outcomes of attempts to site nuclear reactors over this time period. These findings have important implications in the post‐Fukushima ‘nuclear renaissance’ era when many still hope to revitalize the nuclear industry in the USA. Copyright © 2016 John Wiley & Sons, Ltd.     

The Hinterland Urbanised?

What defines the urban? And can the non-urban necessarily always be classified as rural? Neil Brenner , Director of the Urban Theory Lab at Harvard University Graduate School of Design, reflects on the lack of an overarching theory to describe these realms, and argues that what we call the countryside or the hinterland has become key to the process of capitalist urbanisation.     

A look behind the curtain: Measuring the complex economic effects of regional structural funds in Germany

This paper investigates the mutual impact channels of Germany's major regional policy instrument (GRW) on regional economic development. Different from earlier studies which have predominately focused on a partial assessment of output effects, we explicitly endogenize the factor inputs of the underlying production function. This allows us to comprehensively assess the role of the GRW in driving per capita output, employment, human and physical capital intensities as well as the region's technological growth. The results from a spatial panel vector autoregressive model show that GRW funding has significant positive effects on regional output, the employment rate and human capital intensity.     

Lubrication Mechanism of Phosphonium Phosphate Ionic Liquid Additive in Alkylborane–Imidazole Complexes

The assessment of ionic liquids (ILs) as lubricants in several tribological systems has shown their ability to provide remarkable reduced friction and protection against wear, whether they are used as additives or in the neat form. However, their corrosion and limited solubility in non-polar hydrocarbon oils represent the bottleneck-limiting factors for the use of ILs as lubricants. Therefore, in order to tackle these problems, mixtures of alkylborane–imidazole complexes with one halogen-free IL as additive were used in this study. The knowledge of the additive–surface interactions and hence the understanding of tribological properties are an important issue for lubricant formulations and were also investigated in this work. Thus, combination effects between two ionic liquid additives, a halogenated and a halogen-free one, were evaluated by a ball-on-disc-type tribometer under boundary lubrication conditions. Effective friction reduction and anti-wear properties have been demonstrated in tribological investigations when adding between 0.7 and 3.4 wt% of the halogen-free IL into base fluid composed of alkylborane–imidazole complexes. X-ray photoelectron spectroscopy analyses of the steel specimens were conducted to study the correlation between tribological properties and chemical surface composition of the boundary films formed on the rubbing surface. This work suggests potential applications for using halogen-free ILs as additives for synthetic ionic liquid lubricants.     

Fast start-up of a diesel fuel processor for PEM fuel cells

Fuel cell systems based on liquid fuels are particularly suitable for auxiliary power generation due to the high energy density of the fuel and its easy storage. Together with industrial partners, Oel-Waerme-Institut is developing a 3 kW_el PEM fuel cell system based on diesel steam reforming to be applied as an APU for caravans and yachts. The start-up time of a fuel cell APU is of crucial importance since a buffer battery has to supply electric power until the system is ready to take over. Therefore, the start-up time directly affects the battery capacity and consequently the system size, weight, and cost.     

Opto-electronic high-frequency cross-correlation using avalanche photodiodes

Correlation analysis has become an important research tool in the investigation of signals and systems behaviour. We report on a special opto-electronic cross-correlator in which a silicon avalanche photodiode is used as the main component. The internal gain of this photodiode is pulse-modulated with 330 ps FWHM at 126 MHz repetition rate, or is modulated sinusoidally at frequencies of up to 882 MHz, respectively. In the pulsed mode, very weak repetitive optical pulses can be detected with 3 × 10⁻³ photons per pulse sensitivity, and with 10 ps timing accuracy. The second mode offers time-selective signal rejection capabilities with 3 ps time resolution. The opto-electronic cross-correlator can be used in displacement and distance measurement, robotics, time dispersion analysis in optical fibres, transient absorption spectroscopy, fluorescence decay measurement, lifetime-selective fluorescence detection, and in fluorescence signal suppression in Raman spectroscopy.