6,248 research outputs found
On the distribution of modulo one in imaginary quadratic number fields with class number one
We investigate the distribution of modulo one in imaginary
quadratic number fields with class number one,
where is restricted to prime elements in the ring of integers of . In analogy to classical work due to R.
C. Vaughan, we obtain that the inequality is satisfied for infinitely many , where
measures the distance of to
and denotes the norm of .
The proof is based on Harman's sieve method and employs number field
analogues of classical ideas due to Vinogradov. Moreover, we introduce a
smoothing which allows us to make conveniently use of the Poisson summation
formula.Comment: 36 page
Analysing the implication of the EU 20-10-20 targets for world vegetable oil production
The European Commission proposes a minimum of 10 % biofuels in the total transport fuel use by 2020. The new 10% minimum target in 2020 is combined with the existing regulation, which fixes the target at 5.75% in 2010. This paper will in particular investigates how a full implementation of the 20- 10-20 targets would affect production and trade of oil plants in the EU and its main trade partners on this commodity markets, particularly Malaysia and Indonesia. The global general equilibrium model GLOBE is used to carry out the policy scenarios and to assess the effects on oil palm plantation area in Malaysia and Indonesia. The results show that the increased EU bio-diesel target will not significantly influence the expansion of palm oil production in Indonesia and Malaysia.Crop Production/Industries, International Relations/Trade, Resource /Energy Economics and Policy,
Spin transport in graphene/transition metal dichalcogenide heterostructures
Since its discovery, graphene has been a promising material for spintronics:
its low spin-orbit coupling, negligible hyperfine interaction, and high
electron mobility are obvious advantages for transporting spin information over
long distances. However, such outstanding transport properties also limit the
capability to engineer active spintronics, where strong spin-orbit coupling is
crucial for creating and manipulating spin currents. To this end, transition
metal dichalcogenides, which have larger spin-orbit coupling and good interface
matching, appear to be highly complementary materials for enhancing the
spin-dependent features of graphene while maintaining its superior charge
transport properties. In this review, we present the theoretical framework and
the experiments performed to detect and characterize the spin-orbit coupling
and spin currents in graphene/transition metal dichalcogenide heterostructures.
Specifically, we will concentrate on recent measurements of Hanle precession,
weak antilocalization and the spin Hall effect, and provide a comprehensive
theoretical description of the interconnection between these phenomena.Comment: 21 pages, 11 figures. This document is the unedited Author's version
of a Submitted Work that was subsequently accepted for publication in Nano
Letters, copyright\c{opyright}American Chemical Society after peer review. To
access the final edited and published work see
http://pubs.rsc.org/en/Content/ArticleLanding/2018/CS/C7CS00864
Fluid-Structure Interaction Simulation of a Coriolis Mass Flowmeter using a Lattice Boltzmann Method
In this paper we use a fluid-structure interaction (FSI) approach to simulate
a Coriolis mass flowmeter (CMF). The fluid dynamics are calculated by the open
source framework OpenLB, based on the lattice Boltzmann method (LBM). For the
structural dynamics we employ the open source software Elmer, an implementation
of the finite element method (FEM). A staggered coupling approach between the
two software packages is presented. The finite element mesh is created by the
mesh generator Gmsh to ensure a complete open source workflow. The Eigenmodes
of the CMF, which are calculated by modal analysis are compared with
measurement data. Using the estimated excitation frequency, a fully coupled,
partitioned, FSI simulation is applied to simulate the phase shift of the
investigated CMF design. The calculated phaseshift values are in good agreement
to the measurement data and verify the suitability of the model to numerically
describe the working principle of a CMF
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