61,905 research outputs found
New business and economic models in the connected digital economy
This paper discusses business models as a systemic phenomenon as opposed to traditional reductionistic approaches of business disciplines. It presents the ways connectivity change economic models due to the availability of consumption data as an economic resource, markets forming at consumption spaces, and how industries could disrupt one another when connected through consumption technologies. The paper further suggests that the challenges posed by connectivity results in the redrawing of traditional firm and market boundaries. It proposes for more research into modularity, transaction costs, the future role of the firm, and the necessary transformation of businesses to stay agile in a connected digital economy
A Constrained Tectonics Model for Coronal Heating
An analytical and numerical treatment is given of a constrained version of
the tectonics model developed by Priest, Heyvaerts, & Title [2002]. We begin
with an initial uniform magnetic field that is
line-tied at the surfaces and . This initial configuration is
twisted by photospheric footpoint motion that is assumed to depend on only one
coordinate () transverse to the initial magnetic field. The geometric
constraints imposed by our assumption precludes the occurrence of reconnection
and secondary instabilities, but enables us to follow for long times the
dissipation of energy due to the effects of resistivity and viscosity. In this
limit, we demonstrate that when the coherence time of random photospheric
footpoint motion is much smaller by several orders of magnitude compared with
the resistive diffusion time, the heating due to Ohmic and viscous dissipation
becomes independent of the resistivity of the plasma. Furthermore, we obtain
scaling relations that suggest that even if reconnection and/or secondary
instabilities were to limit the build-up of magnetic energy in such a model,
the overall heating rate will still be independent of the resistivity
Solid state morphology and band gap studies of ETS-10 supported CdS nanoparticles
Engelhard titanosilicate (ETS-10) supported cadmium sulphide (CdS) nanoparticles were synthesized and characterized by various solid state techniques including: XRD, DR UV-Vis, TEM and FESEM. The effect of different synthesis routes of CdS nanoparticles on its physicochemical character was studied. It was observed that CdS nanoparticles prepared by both in situ sulphur reduction (CdS-IS) and reverse micelle (CdS-RM) methods showed similar properties. However, CdS-IS nanoparticles are more feasible and economically practical. The reflectance measurements of the as-synthesized CdS nanoparticles are apparently blue-shifted compared to bulk CdS. This phenomenon of blue-shifted absorption edge has been ascribed to an increase in bandgap energy with a decrease in particle sizes. The bandgap of the as-synthesized CdS samples was calculated from the linear correlation of [F(R) h?]2 and h?. The bandgap of CdS in ETS-10 was noticeably slightly reduced when compared with the as-synthesized CdS (8 nm) due to the formation of cluster arrays on the pores of ETS-10
Coronal and interplanetary propagation, interplanetary acceleration, cosmic-ray observations by deep space network and anomalous component
The purpose is to provide an overview of the contributions presented in sessions SH3, SH1.5, SH4.6 and SH4.7 of the 19th International Cosmic Ray Conference. These contributed papers indicate that steady progress continues to be made in both the observational and the theoretical aspects of the transport and acceleration of energetic charged particles in the heliosphere. Studies of solar and interplanetary particles have placed emphasis on particle directional distributions in relation to pitch-angle scattering and magnetic focusing, on the rigidity and spatial dependence of the mean free path, and on new propagation regimes in the inner and outer heliosphere. Coronal propagation appears in need of correlative multi-spacecraft studies in association with detailed observation of the flare process and coronal magnetic structures. Interplanetary acceleration has now gone into a consolidation phase, with theories being worked out in detail and checked against observation
Determination of the pitch-angle distribution and transverse anisotropy of interplanetary particles
A method to determine the directional differential intensity (d.d.i.), expressed in terms of spherical harmonics, from sectored particle data, concurrent interplanetary magnetic field (IMF) and solar wind velocity is presented
Experiments on the dynamic behavior of cavitating pumps
This paper describes experiments performed to measure the dynamic transfer matrices for cavitating (and noncavitating) pumps. These transfer matrices describe the relationship between small linear oscillatory perturbations in the pressures and mass flow rates at inlet and discharge from the hydraulic machine. The matrices were deduced from direct measurements of these fluctuating quantities for different modes of excitation of the machine. Results for a cavitating inducer are presented as functions of frequency and mean operating state. Though some of the trends in the data are consistent with existing theoretical models of inducer dynamics, others are not, indicating a need for further theoretical investigation of the dynamic characteristics of such flows. The results exhibit increasingly complex dynamics with increasing cavitation; it appears that the hydraulic machine deviates from an essentially passive response without cavitation to an increasingly active response as the cavitation number is reduced
High Magnetic Field Rotation-powered Pulsars
Anomalous X-ray pulsars and soft gamma repeaters have recently emerged as a
unified class of neutron stars, identified by dramatic X-ray and gamma-ray
outbursts and via luminous X-ray pulsations, both thought to be powered by the
decay of an enormous internal magnetic field. This "magnetar" hypothesis has
raised the question of these objects' physical relationship with conventional
rotation-powered pulsars (RPPs). The highest magnetic-field RPPs might
therefore be expected to be transition objects between the two populations. The
recently reported magnetar-like outburst of PSR J1846-0258, previously thought
to be purely rotation-powered, clearly supports this suggestion. Here we review
the observational properties of the highest magnetic-field RPPs known, and show
some common characteristics that are notable among RPPs, which are plausibly
related to their high fields. Using these objects, we consider the evidence for
proposed "magneto-thermal evolution" in neutron stars, and argue that while
some exists, it is not yet conclusive.Comment: 6 pages, 4 figures, Conference proceeding of "ASTROphysics of Neutron
Stars 2010 -- a conference in honor of M. Ali Alpar", 2-6 August 2010, Cesme,
Izmir, Turke
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