258 research outputs found
'Cloudbuster':a Python-based open source application for three-dimensional reconstruction and quantification of stacked biological imaging samples
Time-resolved impulse response of the magnetoplasmon resonance in a two-dimensional electron gas
We have used optically excited ultrashort electrical pulses to measure the
magnetoplasmon resonance of a two-dimensional electron gas formed in an
AlGaAs/GaAs heterostructure at frequencies up to 200 gigahertz. This is
accomplished by incorporating the sample into a guided wave probe operating in
a pumped (^{3}He) system. We are able to detect the resonance by launching a
stimulus pulse in the guide, and monitoring the system response in a time
resolved pump-probe arrangement. Data obtained from measurements yield resonant
frequencies that agree with the magnetoplasmon dispersion relation.Comment: 4 pages, 4 figure
Self-aligned nanoscale SQUID on a tip
A nanometer-sized superconducting quantum interference device (nanoSQUID) is
fabricated on the apex of a sharp quartz tip and integrated into a scanning
SQUID microscope. A simple self-aligned fabrication method results in
nanoSQUIDs with diameters down to 100 nm with no lithographic processing. An
aluminum nanoSQUID with an effective area of 0.034 m displays flux
sensitivity of 1.8 \mu_B/\mathrm{Hz}^{1/2}$ and high bandwidth, the SQUID on a tip is a highly
promising probe for nanoscale magnetic imaging and spectroscopy.Comment: 14 manuscript pages, 5 figure
Magnetic susceptibility of the normal-superconducting transition in high-purity single-crystal α-uranium
We report complex ac magnetic susceptibility measurements of a superconducting transition in very high-quality single-crystal alpha-uranium using microfabricated coplanar magnetometers. We identify an onset of superconductivity at Tapproximate to0.7 K in both the real and imaginary components of the susceptibility which is confirmed by resistivity data. A superconducting volume fraction argument, based on a comparison with a calibration YBa2Cu3O7-delta sample, indicates that superconductivity in these samples may be filamentary. Our data also demonstrate the sensitivity of the coplanar micro-magnetometers, which are ideally suited to measurements in pulsed magnetic fields exceeding 100 T
Not Doomed to Death: A Map of Small Firms' Business Models in the Italian Textile Apparel Industry
Avaliação de empresas por múltiplos aplicados em empresas agrupadas com análise de cluster
What lies between market and hierarchy? Insights from internalization theory and global value chain theory
In this paper, we suggest that internalization theory might be extended by incorporating complementary insights from GVC theory. More specifically, we argue that internalization theory can explain why lead firms might wish to externalize selected activities, but that it is largely silent on the mechanisms by which those lead firms might exercise control over the resultant externalized relationships with their GVC partners. We advance an explanation linking the choice of control mechanism to two factors: power asymmetries between the lead firms and their GVC partners, and the degree of codifiability of the information to be exchanged in the relationship
Starting-up unregistered and firm performance in Turkey
© 2016 The Author(s) Recent years have seen a questioning of the negative representation of informal sector entrepreneurship and an emergent view that it may offer significant benefits. This paper advances this rethinking by evaluating the relationship between business registration and future firm performance. Until now, the assumption has been that starting-up unregistered is linked to weaker firm performance. Using World Bank Enterprise Survey data on 2494 formal enterprises in Turkey, and controlling for other determinants of firm performance as well as the endogeneity of the registration decision, the finding is that formal enterprises that started-up unregistered and spent longer unregistered have significantly higher subsequent annual sales and productivity growth rates compared with those registered from the outset. This is argued to be because in such weak institutional environments, the advantages of registering from the outset are outweighed by the benefits of deferring business registration and the low risks of detection and punishment. The resultant implication is that there is a need to shift away from the conventional eradication approach based on the negative depiction of informal entrepreneurship as poorly performing, and towards a more facilitating approach that improves the benefits of business registration and tackles the systemic formal institutional deficiencies that lead entrepreneurs to decide to delay the registration of their ventures
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