24,211 research outputs found
Adolf Reinach: An Intellectual Biography
The essay provides an account of the development of Reinach’s philosophy of “Sachverhalte” (states of affairs) and on problems in the philosophy of law, leading up to his discovery of the theory of speech acts in 1913. Reinach’s relations to Edmund Husserl and to the Munich phenomenologists are also dealt with
On the Fourier transform of the characteristic functions of domains with -smooth boundary
We consider domains with -smooth boundary and
study the following question: when the Fourier transform of the
characteristic function belongs to ?Comment: added two references; added footnotes on pages 6 and 1
Diffractive charged meson pair production
We investigate the possibility to measure the nonforward gluon distribution
function by means of diffractively produced \pi^+\pi^- and K^+K^- pairs in
polarized lepton nucleon scattering. The resulting cross sections are small and
are dominated by the gluonic contribution. We find relatively large spin
asymmetries, both for \pi^+\pi^- and for K^+K^- pairs.Comment: 15 pages, version with changed kinematical cuts, to be pubished in
Phys.Lett.
Positron-inert gas differential elastic scattering
Measurements are being made in a crossed beam experiment of the relative elastic differential cross section (DCS) for 5 to 300 eV positrons scattering from inert gas atoms (He, Ne, Ar, Kr, and Xe) in the angular range from 30 to 134 deg. Results obtained at energies around the positronium (Ps) formation threshold provide evidence that Ps formation and possibly other inelastic channels have an effect on the elastic scattering channel
Role Of Social Presence, Choice Of Online Or Face-To-Face Group Format, And Satisfaction With Perceived Knowledge Gained In A Distance Learning Environment
This mixed-methods study examined factors that contributed to satisfaction with perceived
knowledge gained in a distance learning environment where collaboration represents a major portion of the course structure. Giving learners authority over the physical learning environment and offering different formats for collaboration, either online or in person, contributed to the learners’ overall satisfaction with the course. Results indicate that social presence may not have played a role in choice of
distance learning format
Realistic Magnetohydrodynamical Simulation of Solar Local Supergranulation
Three-dimensional numerical simulations of solar surface magnetoconvection
using realistic model physics are conducted. The thermal structure of
convective motions into the upper radiative layers of the photosphere, the main
scales of convective cells and the penetration depths of convection are
investigated. We take part of the solar photosphere with size of 60x60 Mm in
horizontal direction and by depth 20 Mm from level of the visible solar
surface. We use a realistic initial model of the Sun and apply equation of
state and opacities of stellar matter. The equations of fully compressible
radiation magnetohydrodynamics with dynamical viscosity and gravity are solved.
We apply: 1) conservative TVD difference scheme for the magnetohydrodynamics,
2) the diffusion approximation for the radiative transfer, 3) dynamical
viscosity from subgrid scale modeling. In simulation we take uniform
two-dimesional grid in gorizontal plane and nonuniform grid in vertical
direction with number of cells 600x600x204. We use 512 processors with
distributed memory multiprocessors on supercomputer MVS-100k in the Joint
Computational Centre of the Russian Academy of Sciences.Comment: 6 pages, 5 figures, submitted to the proceedings of the GONG 2008 /
SOHO XXI conferenc
Presence And Interaction In An Inquiry-Based Learning Environment
This mixed-methods study examined how interactions facilitated cognitive, social, and teaching presence in inquiry-based learning in a course where learners had the option to choose whether to conduct group work online or in person. Findings suggest that the knowledge learners gained from the course resulted from chats and discussions within their small groups and not from threaded discussions with the entire class. Results also indicate that learners with a high degree of social presence within their small groups developed a relationship that appeared to
overshadow their relationship with classmates in other groups. Teaching presence may be affected by whether learners choose to collaborate in person or online and by where they choose to collaborate. The further the group moved away from the instructor’s online or physical presence, the lower the degree of teaching presence the learners felt
Thermally induced magnetic relaxation in square artificial spin ice
The properties of natural and artificial assemblies of interacting elements,
ranging from Quarks to Galaxies, are at the heart of Physics. The collective
response and dynamics of such assemblies are dictated by the intrinsic
dynamical properties of the building blocks, the nature of their interactions
and topological constraints. Here we report on the relaxation dynamics of the
magnetization of artificial assemblies of mesoscopic spins. In our model
nano-magnetic system - square artificial spin ice - we are able to control the
geometrical arrangement and interaction strength between the magnetically
interacting building blocks by means of nano-lithography. Using time resolved
magnetometry we show that the relaxation process can be described using the
Kohlrausch law and that the extracted temperature dependent relaxation times of
the assemblies follow the Vogel-Fulcher law. The results provide insight into
the relaxation dynamics of mesoscopic nano-magnetic model systems, with
adjustable energy and time scales, and demonstrates that these can serve as an
ideal playground for the studies of collective dynamics and relaxations.Comment: 15 pages, 5 figure
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