2,766 research outputs found
Part III - The effects of thermal stresses on the aerobic and anaerobic work capacities of men Final scientific report
Effects of hyperthermia and hypothermia on aerobic and anaerobic work capacities of me
The effects of dehydration on the aerobic and anaerobic capacities of men, part IV FINAL scientific report
Dehydration effects on work capacity and aerobic capacities of me
The slimming effect of advection on black-hole accretion flows
At super-Eddington rates accretion flows onto black holes have been described
as slim (aspect ratio ) or thick (H/R >1) discs, also known as
tori or (Polish) doughnuts. The relation between the two descriptions has never
been established, but it was commonly believed that at sufficiently high
accretion rates slim discs inflate, becoming thick. We wish to establish under
what conditions slim accretion flows become thick. We use analytical equations,
numerical 1+1 schemes, and numerical radiative MHD codes to describe and
compare various accretion flow models at very high accretion rates.We find that
the dominant effect of advection at high accretion rates precludes slim discs
becoming thick. At super-Eddington rates accretion flows around black holes can
always be considered slim rather than thick.Comment: 8 pages, 5 figures. Astronomy & Astrophysics, in pres
General purpose technologies : a survey, a critique and future research directions
Since Bresnahan and Trajitenberg’s original 1995 article on ‘General Purpose Technology (GPT): Engines of Growth’, the concept of GPT has slowly but steadily influenced the literature on business ICT (information and communication technology) adoption. In considering business ICT, within the framework of GPT allows to focus on the externalities in ICT adoption which poses challenges for policy and society as a whole. In the literature, these externality benefits of business ICT have rarely been examined. In this context, the article provides a survey of recently published empirical studies (from 2004 to 2013) citing the original article of Bresnahan and Trajenberg. In using the science citation index and citations derived from Google Scholar, we found 1090 articles fulfilling these criteria; from these articles just 57 studies provided some empirical estimation of the productivity impact of ICT. Our survey indicates if GPT refers to whole range of ICT, this might generate misleading results. In general, our results indicate a shift in the discussion on GPT focusing on business ICT. The literature demonstrates that - with the availability of better data - increasingly a better distinction between infrastructure technologies and applications should be used. While infrastructure technologies are uniformly adopted among small and large enterprises, the adoption of applications is a more complex phenomenon. Although some authors argue that there is a productivity impact of ICT, this impact is mediated by employment, wage and size variables. In particular, the adoption of business ICT within small and medium-sized enterprises (SMEs) has rarely been examined
Magnetic properties of GaMnAs single layers and GaInMnAs superlattices investigated at low temperature and high magnetic field
Magnetotransport properties of GaMnAs single layers and InGaMnAs/InGaAs
superlattice structures were investigated at temperatures from 4 K to 300 K and
magnetic fields up to 23 T to study the influence of carriers confinement
through different structures. Both single layers and superlattice structures
show paramagnetic-to-ferromagnetic phase transition. In GaMnAs/InGaAs
superlattice beside the Curie temperature (Tc ~ 40 K), a new phase transition
is observed close to 13 K.Comment: 8 pages, 5 figures, Proceedings of the XXXII International School on
the Physics of Semiconducting Compounds, Jaszowiec 2003, Polan
Informe acerca de las investigaciones arqueoastronómicas en el área central de Ingapirca (Ecuador)
Sin resume
The adoption of information and communication technologies in the desing sector and their impact on firm performance : evidence from the Dutch Design sector
This paper analyzes processes and effects of ICT enabled innovation in the Dutch design sector. Although the adoption of Information and Communication Technologies (ICT) is considered as vital in the design sector, little is known about whether and how ICTs affect the firm performance of small and medium-sized companies (SMEs) in the industry. In introducing a conceptual distinction between ICT supporting the information processing and communication, the paper first examines the determinants of ICT adoption. Next, we analyze the effects of ICT adoption on product and process innovation as well as on firm performance, focusing on the mediating role of the innovation processes. The analyses rest on survey data of a sample of 189 Dutch companies in the Web, Graphic, and Industrial Design Sector in the Netherlands. The results indicate that information processing role of ICT supports the exploitation and communication role facilitates the exploration in organizational learning. The exploitation enables process innovation while exploration enables product innovation. Lastly, Information processing technologies and product innovation are important determinants of superior firm performance
Weak localization in ferromagnetic (Ga,Mn)As nanostructures
We report on the observation of weak localization in arrays of (Ga,Mn)As
nanowires at millikelvin temperatures. The corresponding phase coherence length
is typically between 100 nm and 200 nm at 20 mK. Strong spin-orbit interaction
in the material is manifested by a weak anti-localization correction around
zero magnetic field.Comment: 5 pages, 3 figure
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