39,910 research outputs found
Noise measurements for various configurations of a model of a mixer nozzle externally blown flap system
Noise data were taken for variations to a large scale model of an externally blown flap lift augmentation system. The variations included two different mixer nozzles (7 and 8 lobes), two different wing models (2 and 3 flaps), and different lateral distances between the wing chord line and the nozzle centerline. When the seven lobe was used with the trailing flap in the 60 deg position, increasing the wing to nozzle distance had no effect on the sound level. When the eight lobe nozzle was used there was a decrease in sound level. With the 20 deg flap setting the noise level decreased when the distance was increased using either nozzle
Remote sensing in Michigan for land resource management
The utilization of NASA earth resource survey technology as an important aid in the solution of current problems in resource management and environmental protection in Michigan is discussed. Remote sensing techniques to aid Michigan government agencies were used to achieve the following results: (1) provide data on Great Lakes beach recession rates to establish shoreline zoning ordinances; (2) supply technical justification for public acquisition of land to establish the St. John's Marshland Recreation Area; (3) establish economical and effective methods for performing a statewide wetlands survey; (4) accomplish a variety of regional resource management actions in the Upper Peninsula; and (5) demonstrate improved soil survey methods. The project disseminated information on remote sensing technology and provided advice and assistance to a number of users in Michigan
High Harmonic Generation in SF: Raman-excited Vibrational Quantum Beats
In a recent experiment (N. Wagner et al., PNAS v103, p13279) on SF, a
high-harmonic generating laser pulse is preceded by a pump pulse which
stimulates Raman-active modes in the molecule. Varying the time delay between
the two pulses modulates high harmonic intensity, with frequencies equal to the
vibration frequencies of the Raman-active modes. We propose an explanation of
this modulation as a quantum interference between competing pathways that occur
via adjacent vibrational states of the molecule. The Raman and high harmonic
processes act as beamsplitters, producing vibrational quantum beats among the
Raman-active vibrational modes that are excited by the first pulse. We
introduce a rigorous treatment of the electron-ion recombination process and
the effect of the ionic Coulomb field in the electron propagation outside the
molecule, improving over the widely-used three-step model.Comment: submitted to PR
Communication on the science-policy interface: An overview of conceptual models
This article focuses on scholarly discourse on the science-policy interface, and in particular on questions regarding how this discourse can be understood in the course of history and which lessons we can learn. We aim to structure the discourse, show kinships of different concepts, and contextualize these concepts. For the twentieth century we identify three major phases that describe interactions on the science policy interface: the “linear phase” (1960s–1970s) when science informed policy-making in a unidirectional manner, the “interactive phase” (1970–2000s) when both sides found themselves in a continuous interaction, and the “embedded phase” (starting from the 2000s) when citizens’ voices come to be involved within this dialogue more explicitly. We show that the communicative relationship between science and policy-making has become more complex over time with an increasing number of actors involved. We argue that better skill-building and education can help to improve communication within the science-policy interface
Detection of SUSY Signals in Stau Neutralino Co-annihilation Region at the LHC
We study the prospects of detecting the signal in the stau neutralino
co-annihilation region at the LHC using tau leptons. The co-annihilation signal
is characterized by the stau and neutralino mass difference (dM) to be 5-15 GeV
to be consistent with the WMAP measurement of the cold dark matter relic
density as well as all other experimental bounds within the minimal
supergravity model. Focusing on tau's from neutralino_2 --> tau stau --> tau
tau neutralino_1 decays in gluino and squark production, we consider inclusive
MET+jet+3tau production, with two tau's above a high E_T threshold and a third
tau above a lower threshold. Two observables, the number of opposite-signed tau
pairs minus the number of like-signed tau pairs and the peak position of the
di-tau invariant mass distribution, allow for the simultaneous determination of
dM and M_gluino. For dM = 9 GeV and M_gluino = 850 GeV with 30 fb^-1 of data,
we can measure dM to 15% and M_gluino to 6%.Comment: 4 pages LaTex, 3 figures. To appear in Proceedings of SUSY06, the
14th International Conference on Supersymmetry and the Unification of
Fundamental Interactions, UC Irvine, California, 12-17 June 2006. A typo in a
reference is correcte
Remote sensing in Michigan for land resource management
The application of NASA earth resource survey technology to resource management and environmental protection in Michigan was investigated. Remote sensing techniques to aid Michigan government agencies were applied in the following activities: (1) land use inventory and management, (2) great lakes shorelands protection and management, (3) wetlands protection and management, and (4) soil survey. In addition, information was disseminated on remote sensing technology, and advice and assistance was provided to a number of users
Comment on ''the controlled charge ordering and evidence of the metallic state in PrCaMnO films''
In a recent paper (2000 \QTR{it}{J. Phys.: Condens. Matter} \QTR{bf}{12}
L133) Lee \QTR{it}{et al.} have studied the transport properties of
PrCaMnO thin films. They claimed that they are able to
controlled the charge-ordered (CO) state by the lattice strains. We propose
herein another alternative since another indexation of the orientation of the
film can be found leading to almost no distortion of the cell, as compared to
the bulk compound.Comment: 2 page
Exploring complex networks by walking on them
We carry out a comparative study on the problem for a walker searching on
several typical complex networks. The search efficiency is evaluated for
various strategies. Having no knowledge of the global properties of the
underlying networks and the optimal path between any two given nodes, it is
found that the best search strategy is the self-avoid random walk. The
preferentially self-avoid random walk does not help in improving the search
efficiency further. In return, topological information of the underlying
networks may be drawn by comparing the results of the different search
strategies.Comment: 5 pages, 5 figure
Non-universality of artificial frustrated spin systems
Magnetic frustration effects in artificial kagome arrays of nanomagnets with
out-of-plane magnetization are investigated using Magnetic Force Microscopy and
Monte Carlo simulations. Experimental and theoretical results are compared to
those found for the artificial kagome spin ice, in which the nanomagnets have
in-plane magnetization. In contrast with what has been recently reported, we
demonstrate that long range (i.e. beyond nearest-neighbors) dipolar
interactions between the nanomagnets cannot be neglected when describing the
magnetic configurations observed after demagnetizing the arrays using a field
protocol. As a consequence, there are clear limits to any universality in the
behavior of these two artificial frustrated spin systems. We provide arguments
to explain why these two systems show striking similarities at first sight in
the development of pairwise spin correlations.Comment: 7 pages, 6 figure
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