103 research outputs found
Measurement of Blade Deflection of an Unmanned Intermeshing Rotor Helicopter
The dynamic behavior of intermeshing rotor blades is complex and subjected to rotor-rotor-interactions like oblique blade-vortex and blade-wake interactions. To gain a better understanding of these effects a blade deflection measurement method is proposed in this paper. The method is based on a single camera per rotor blade depicting the rotor blade from a position fixed to the rotor head. Due to the mounting position of the camera close to the rotational plane the method is called In-Plane Blade Deflection Measurement (IBDM). The basic principles, data processing and measurement accuracy are presented in the paper. The major advantages of the proposed method are the applicability to both, flight and wind tunnel trials, as well as the usability for multi-rotor configurations having a significant rotor overlap. Furthermore comparisons to other blade deflection measurement methods are presented. Finally, experimental data of a flight test of an unmanned intermeshing helicopter is presented
Children's Planning Performance in the Zoo Map Task (BADS-C) : Is It Driven by General Cognitive Ability, Executive Functioning, or Prospection?
Preparation of this article was partially funded by the Swiss National Science Foundation (SNSF; 100014_152841) and the Natural Sciences and Engineering Council of Canada (NSERC; RGPIN-2015-03774).Peer reviewedPostprin
The J_1-J_2 antiferromagnet with Dzyaloshinskii-Moriya interaction on the square lattice: An exact diagonalization study
We examine the influence of an anisotropic interaction term of
Dzyaloshinskii-Moriya (DM) type on the groundstate ordering of the J_1-J_2
spin-1/2-Heisenberg antiferromagnet on the square lattice. For the DM term we
consider several symmetries corresponding to different crystal structures. For
the pure J_1-J_2 model there are strong indications for a quantum spin liquid
in the region of 0.4 < J_2/J_1 < 0.65. We find that a DM interaction influences
the breakdown of the conventional antiferromagnetic order by i) shifting the
spin liquid region, ii) changing the isotropic character of the groundstate
towards anisotropic correlations and iii) creating for certain symmetries a net
ferromagnetic moment.Comment: 7 pages, RevTeX, 6 ps-figures, to appear in J. Phys.: Cond. Ma
RCSB PDB Mobile: iOS and Android mobile apps to provide data access and visualization to the RCSB Protein Data Bank.
SummaryThe Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) resource provides tools for query, analysis and visualization of the 3D structures in the PDB archive. As the mobile Web is starting to surpass desktop and laptop usage, scientists and educators are beginning to integrate mobile devices into their research and teaching. In response, we have developed the RCSB PDB Mobile app for the iOS and Android mobile platforms to enable fast and convenient access to RCSB PDB data and services. Using the app, users from the general public to expert researchers can quickly search and visualize biomolecules, and add personal annotations via the RCSB PDB's integrated MyPDB service.Availability and implementationRCSB PDB Mobile is freely available from the Apple App Store and Google Play (http://www.rcsb.org)
The spin 1/2 Heisenberg star with frustration II: The influence of the embedding medium
We investigate the spin 1/2 Heisenberg star introduced in J. Richter and A.
Voigt, J. Phys. A: Math. Gen. {\bf 27}, 1139 (1994). The model is defined by
; , . In extension to the Ref. we consider a more general
describing the properties of the spins surrounding the
central spin . The Heisenberg star may be considered as an essential
structure element of a lattice with frustration (namely a spin embedded in a
magnetic matrix ) or, alternatively, as a magnetic system with a
perturbation by an extra spin. We present some general features of the
eigenvalues, the eigenfunctions as well as the spin correlation of the model. For being a linear chain, a square
lattice or a Lieb-Mattis type system we present the ground state properties of
the model in dependence on the frustration parameter .
Furthermore the thermodynamic properties are calculated for being a
Lieb--Mattis antiferromagnet.Comment: 16 pages, uuencoded compressed postscript file, accepted to J. Phys.
A: Math. Ge
Biofuel Blending Reduces Aircraft Engine Particle Emissions at Cruise Conditions
Aviation aerosol emissions have a disproportionately large climatic impact because they are emitted high in the relatively pristine upper troposphere where they can form linear contrails and influence cirrus clouds. Research aircraft from NASA, DLR, and NRC Canada made airborne measurements of gaseous and aerosol composition and contrail microphysical properties behind the NASA DC-8 aircraft at cruise altitudes. The DC-8 CFM-56-2C engines burned traditional medium-sulfur Jet A fuel as well as a low-sulfur Jet A fuel and a 50:50 biofuel blend. Substantial, two-to-three-fold emissions reductions are found for both particle number and mass emissions across the range of cruise thrust operating conditions. These observations provide direct and compelling evidence for the beneficial impacts of biojet fuel blending under real-world conditions
Π‘ΠΎΠ²Π΅ΡΡΠ΅Π½ΡΡΠ²ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠΈΡΡΠ΅ΠΌΡ ΠΌΠΎΡΠΈΠ²Π°ΡΠΈΠΈ ΠΈ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΡΡΠ΄Π° ΡΠ°Π±ΠΎΡΠ½ΠΈΠΊΠΎΠ² Π½Π° ΠΏΡΠΈΠΌΠ΅ΡΠ΅ ΠΠΠ "Π ΠΎΡΡΠ΅Π»Π΅ΠΊΠΎΠΌ"
ΠΠ±ΡΠ΅ΠΊΡ ΠΠΠ - ΡΠΈΡΡΠ΅ΠΌΠ° ΠΌΠΎΡΠΈΠ²Π°ΡΠΈΠΈ ΠΈ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΏΠ΅ΡΡΠΎΠ½Π°Π»Π°. Π¦Π΅Π»Ρ ΠΠΠ β ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠ΅ΠΉ ΡΠΈΡΡΠ΅ΠΌΡ ΠΌΠΎΡΠΈΠ²Π°ΡΠΈΠΈ ΠΈ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΡΡΠ΄Π° ΡΠ°Π±ΠΎΡΠ½ΠΈΠΊΠΎΠ² ΠΠΠ "Π ΠΎΡΡΠ΅Π»Π΅ΠΊΠΎΠΌ" ,Π°Π½Π°Π»ΠΈΠ· ΠΏΡΠΈΠΌΠ΅Π½ΡΠ΅ΠΌΡΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΠΌΠΎΡΠΈΠ²Π°ΡΠΈΠΈ ΠΈ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠ° ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°ΡΠΈΠΉ. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π±ΡΠ» ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½ ΡΡΠ΄ ΠΌΠ΅ΡΠΎΠΏΡΠΈΡΡΠΈΠΉ ΠΏΠΎ ΡΠΎΠ²Π΅ΡΡΠ΅Π½ΡΡΠ²ΠΎΠ²Π°Π½ΠΈΡ ΡΠΈΡΡΠ΅ΠΌΡ ΠΌΠΎΡΠΈΠ²Π°ΡΠΈΠΈ ΠΈ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΏΠ΅ΡΡΠΎΠ½Π°Π»ΠΎΠΌ.Object of WKR is a system of motivation and incentives for staff. The purpose of WKR is to study the features of the system of motivation and motivation of the work of PAO "Rostelecom" employees, analyze the methods of motivation and incentives used and develop recommendations. As a result of the research, a number of measures were developed to improve the system of motivation and incentives for staff
Strategic Choices for Redistribution and the Veil of Ignorance: Theory and Experimental Evidence
We provide experimental evidence on the emergence of redistributive societies. Individuals first vote on redistribution by feet and then learn their productivity and invest. We vary the individuals' information about their productivities at the time when they choose a distribution rule and find that there is more redistribution behind a veil of ignorance than under full information. However, the scope of redistribution is less sensitive towards the degree of uncertainty than predicted. For all degrees of uncertainty, we find a coexistence of libertarianism and redistribution as well as incomplete sorting, so that heterogeneous redistribution communities turn out to be sustainable
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