1,970 research outputs found
A graphene bilayer channel transistor with a very high Ion/Ioff ratio, graphene single electron devices and graphene nano-mechanical structures for NEMS
Flipped classroom: a student experience
This is an opinion piece from a paramedic student who was introducted to the concept of flipped classroom. Hacing previously studied at higher education, this was a new way of learning and required an element of pre-learning and enhanced engagement. This is written from the student's view-point, touching on the positives and negatives of her experience, as well as introducing the model of flipped learning
Light-front CQM calculations of baryon electromagnetic form factors
The parameter-free predictions for the and electromagnetic transition form factors, obtained within our
light-front constituent quark model using eigenfunctions of a baryon mass
operator which includes a large amount of configuration mixing, are reported.
The effects due to small components in the baryon wave functions, such as S'-
and D-wave, are also investigated.Comment: to appear in the Proceedings of the International Workshop on Hadron
Dynamics with the new DAPHNE and CEBAF facilities, Frascati, Italy, 11-14
November 199
Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing
© 2016 IOP Publishing Ltd. In aeronautical research experimental data sets of high quality are essential to verify and improve simulation algorithms. For this reason the experimental techniques need to be constantly refined. The shape, movement or deformation of structural aircraft elements can be measured implicitly in multiple ways; however, only optical, correlation-based techniques are able to deliver direct high-order and spatial results. In this paper two different optical metrologies are used for on-ground preparation and the actual execution of in-flight wing deformation measurements on a PW-6U glider. Firstly, the commercial PONTOS system is used for static tests on the ground and for wind tunnel investigations to successfully certify an experimental sensor pod mounted on top of the test bed fuselage. Secondly, a modification of the glider is necessary to implement the optical method named image pattern correlation technique (IPCT), which has been developed by the German Aerospace Center DLR. This scientific technology uses a stereoscopic camera set-up placed inside the experimental pod and a stochastic dot matrix applied to the area of interest on the glider wing to measure the deformation of the upper wing surface in-flight. The flight test installation, including the preparation, is described and results are presented briefly. Focussing on the compensation for typical error sources, the paper concludes with a recommended procedure to enhance the data processing for better results. Within the presented project IPCT has been developed and optimized for a new type of test bed. Adapted to the special requirements of the glider, the IPCT measurements were able to deliver a valuable wing deformation data base which now can be used to improve corresponding numerical models and simulations
Interferometric science results on young stellar objects
Long-baseline interferometry at infrared wavelengths allows the innermost
regions around young stars to be observed. These observations directly probe
the location of the dust and gas in the disks. The characteristic sizes of
these regions found are larger than previously thought. These results have
motivated in part a new class of models of the inner disk structure, but the
precise understanding of the origin of these low visibilities is still in
debate. Mid-infrared observations probe disk emission over a larger range of
scales revealing mineralogy gradients in the disk. Recent spectrally resolved
observations allow the dust and gas to be studied separately showing that the
Brackett gamma emission can find its origin either in a wind or in a
magnetosphere and that there is probably no correlation between the location of
the Brackett gamma emission and accretion. In a certain number of cases, the
very high spatial resolution reveals very close companions and can determine
their masses. Overall, these results provide essential information on the
structure and the physical properties of close regions surrounding young stars
especially where planet formation is suspected to occur.Comment: 18 pages, 6 figures, invited lecture at the VLTI school on
"Astrometry and Imaging with the Very Large Telescope Interferometer", 2-13
June 2008, Keszthely, Hungary. v2: typos corrected; v3: reference adde
Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate_N simulation model
Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the
environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to
quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China,
non-observed pathways of the N cycle were estimated using the EU-Rotate_N simulation model.
EU-Rotate_N was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil
mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between
0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were
satisfactorily simulated by the model for all N treatments except for the traditional N management. The
model predicted high N mineralisation rates and N leaching losses, suggesting that previously published
estimates of N leaching for these production systems strongly underestimated the mineralisation of N
from organic matter
Surface Operators and Knot Homologies
Topological gauge theories in four dimensions which admit surface operators
provide a natural framework for realizing homological knot invariants. Every
such theory leads to an action of the braid group on branes on the
corresponding moduli space. This action plays a key role in the construction of
homological knot invariants. We illustrate the general construction with
examples based on surface operators in N=2 and N=4 twisted gauge theories which
lead to a categorification of the Alexander polynomial, the equivariant knot
signature, and certain analogs of the Casson invariant.
This paper is based on a lecture delivered at the International Congress on
Mathematical Physics 2006, Rio de Janeiro, and at the RTN Workshop 2006,
Napoli.Comment: 37 pages. Based on a talk given at the ICMP 2006 and at the RTN
Workshop 200
The Massive Progenitor of the Type II-Linear Supernova 2009kr
We present early-time photometric and spectroscopic observations of supernova (SN) 2009kr in NGC 1832. We find that its properties to date support its classification as Type II-linear (SN II-L), a relatively rare subclass of core-collapse supernovae (SNe). We have also identified a candidate for the SN progenitor star through comparison of pre-explosion, archival images taken with WFPC2 on board the Hubble Space Telescope with SN images obtained using adaptive optics plus NIRC2 on the 10 m Keck-II telescope. Although the host galaxy's substantial distance (similar to 26 Mpc) results in large uncertainties in the relative astrometry, we find that if this candidate is indeed the progenitor, it is a highly luminous (M(V)(0) = -7.8 mag) yellow supergiant with initial mass similar to 18-24 M(circle dot). This would be the first time that an SN II-L progenitor has been directly identified. Its mass may be a bridge between the upper initial mass limit for the more common Type II-plateau SNe and the inferred initial mass estimate for one Type II-narrow SN.Hungarian OTKA K76816NSF AST-0707769, AST-0908886Sylvia & Jim Katzman FoundationTABASGO FoundationNASA through STScI AR-11248, GO-10877Harvard UniversityUC BerkeleyUniversity of VirginiaNASA/Swift NNX09AQ66GDOEAstronom
Silencing of FGF ‐21 expression promotes hepatic gluconeogenesis and glycogenolysis by regulation of the STAT 3– SOCS 3 signal
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106851/1/febs12767.pd
Broadband antireflection silicon carbide surface by self-assembled nanopatterned reactive-ion etching
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