1,381 research outputs found
Anisotropy of the Stone-Wales Defect and Warping of Graphene Nano-ribbons: A First-principles Analysis
Stone-Wales (SW) defects, analogous to dislocations in crystals, play an
important role in mechanical behavior of -bonded carbon based materials.
Here, we show using first-principles calculations that a marked anisotropy in
the interaction among the SW defects has interesting consequences when such
defects are present near the edges of a graphene nano-ribbon: depending on
their orientation with respect to edge, they result in compressive or tensile
stress, and the former is responsible to depression or warping of the graphene
nano-ribbon. Such warping results in delocalization of electrons in the defect
states.Comment: 8 page
The young cluster NGC 2282 : a multi-wavelength perspective
We present the analysis of the stellar content of NGC~2282, a young cluster
in the Monoceros constellation, using deep optical and IPHAS photometry
along with infrared (IR) data from UKIDSS and -IRAC. Based on the
stellar surface density analysis using nearest neighborhood method, the radius
of the cluster is estimated as 3.15\arcmin. From optical spectroscopic
analysis of 8 bright sources, we have classified three early B-type members in
the cluster, which includes, HD 289120, a previously known B2V type star, a
Herbig Ae/Be star (B0.5 Ve) and a B5 V star. From spectrophotometric analyses,
the distance to the cluster has been estimated as 1.65 kpc. The -band
extinction map is estimated using nearest neighborhood technique, and the mean
extinction within the cluster area is found to be A 3.9 mag. Using
IR colour-colour criteria and H-emission properties, we have
identified a total of 152 candidate young stellar objects (YSOs) in the region,
of which, 75 are classified as Class II, 9 are Class I YSOs. Our YSO catalog
also includes 50 H-emission line sources, identified using slitless
spectroscopy and IPHAS photometry data. Based on the optical and near-IR
colour-magnitude diagram analyses, the cluster age has been estimated to be in
the range of 2 5 Myr, which is in agreement with the estimated age from
disc fraction ( 58\%). Masses of these YSOs are found to be
0.12.0 M. Spatial distribution of the candidate YSOs shows spherical
morphology, more or less similar to the surface density map.Comment: 16 pages, 19 Figure
DNA Of A Successful BPO
This paper identifies some of the critical elements of a successful BPO through a case study of an U.S. financial services firm that had BPO operations in India. The important dimensions of selection, training, motivation, respecting cultural differences, treating quality as paramount in all operations, and understanding how appropriate control has to be exercised in the area of knowledge-intensive services, were identified as being critical to success. Specific propositions are developed based on these critical elements, and provide a potentially new direction to service outsourcing research
Sensory organ like response determines the magnetism of zigzag-edged honeycomb nanoribbons
We present an analytical theory for the magnetic phase diagram for zigzag
edge terminated honeycomb nanoribbons described by a Hubbard model with an
interaction parameter U . We show that the edge magnetic moment varies as ln U
and uncover its dependence on the width W of the ribbon. The physics of this
owes its origin to the sensory organ like response of the nanoribbons,
demonstrating that considerations beyond the usual Stoner-Landau theory are
necessary to understand the magnetism of these systems. A first order magnetic
transition from an anti-parallel orientation of the moments on opposite edges
to a parallel orientation occurs upon doping with holes or electrons. The
critical doping for this transition is shown to depend inversely on the width
of the ribbon. Using variational Monte-Carlo calculations, we show that
magnetism is robust to fluctuations. Additionally, we show that the magnetic
phase diagram is generic to zigzag edge terminated nanostructures such as
nanodots. Furthermore, we perform first principles modeling to show how such
magnetic transitions can be realized in substituted graphene nanoribbons.Comment: 5 pages, 5 figure
- …