1,800 research outputs found
Electronic transport in locally gated graphene nanoconstrictions
We have developed the combination of an etching and deposition technique that
enables the fabrication of locally gated graphene nanostructures of arbitrary
design. Employing this method, we have fabricated graphene nanoconstrictions
with local tunable transmission and characterized their electronic properties.
An order of magnitude enhanced gate efficiency is achieved adopting the local
gate geometry with thin dielectric gate oxide. A complete turn off of the
device is demonstrated as a function of the local gate voltage. Such strong
suppression of device conductance was found to be due to both quantum
confinement and Coulomb blockade effects in the constricted graphene
nanostructures.Comment: 3 pages 3 figures; separated and expanded from arXiv:0705.3044v
On the Hardware Implementation of Triangle Traversal Algorithms for Graphics Processing
Current GPU architectures provide impressive processing rates in graphical applications because of their specialized graphics pipeline. However, little attention has been paid to the analysis and study of different hardware architectures to implement specific pipeline stages. In this work we have identified one of the key stages in the graphics pipeline, the triangle traversal procedure, and we have implemented three different algorithms in hardware: bounding-box, zig-zag and Hilbert curve-based. The experimental results show that important area-performance trade-offs can be met when implementing key image processing algorithms in hardwar
Electronic Transport in Dual-gated Bilayer Graphene at Large Displacement Fields
We study the electronic transport properties of dual-gated bilayer graphene
devices. We focus on the regime of low temperatures and high electric
displacement fields, where we observe a clear exponential dependence of the
resistance as a function of displacement field and density, accompanied by a
strong non-linear behavior in the transport characteristics. The effective
transport gap is typically two orders of magnitude smaller than the optical
band gaps reported by infrared spectroscopy studies. Detailed temperature
dependence measurements shed light on the different transport mechanisms in
different temperature regimes.Comment: 4 pages, 3 figure
Excited state spectroscopy in carbon nanotube double quantum dots
We report on low temperature measurements in a fully tunable carbon nanotube
double quantum dot. A new fabrication technique has been used for the top-gates
in order to avoid covering the whole nanotube with an oxide layer as in
previous experiments. The top-gates allow us to form single dots, control the
coupling between them and we observe four-fold shell filling. We perform
inelastic transport spectroscopy via the excited states in the double quantum
dot, a necessary step towards the implementation of new microwave-based
experiments.Comment: 16 pages, 6 figures, submitted to nanoletter
The Use of Sensors to Prevent, Predict Transition to Chronic and Personalize Treatment of Low Back Pain: A Systematic Review
Non-specific low back pain (NSLBP) is a highly prevalent condition that implies substantial
expenses and affects quality of life in terms of occupational and recreational activities, physical and
psychological health, and general well-being. The diagnosis and treatment are challenging processes
due to the unknown underlying causes of the condition. Recently, sensors have been included in
clinical practice to implement its management. In this review, we furthered knowledge about the
potential benefits of sensors such as force platforms, video systems, electromyography, or inertial
measure systems in the assessment process of NSLBP. We concluded that sensors could identify
specific characteristics of this population like impaired range of movement, decreased stability, or
disturbed back muscular activation. Sensors could provide sufferers with earlier diagnosis, prevention
strategies to avoid chronic transition, and more efficient treatment approaches. Nevertheless, the
review has limitations that need to be considered in the interpretation of results.FEDER/Aragon Government—Dept. of Science, University,
and the Knowledge Society. Grant number [LMP97_21
Are Antarctic Specially Protected Areas safe from plastic pollution? a survey of plastic litter at Byers Peninsula, Livingston Island, Antarctica
A number of studies have reported in the last decades the presence of plastics in the Southern Ocean, which are liable
to reach the coast and accumulate on the Antarctic Continent. Despite this, there are few data on the amount of plastic pollution
on Antarctic beaches below 60°S. Here we provide valuable information about the presence of plastic debris in Byers Peninsula,
Livingston Island, South Shetland Islands, an Antarctic Specially Protected Area (ASPA) and a hotspot for biodiversity. A total
of 129 locations with between 1 and 5 items were recorded among the 3 survey sites on Byers Peninsula. Most of the observed
items are likely to derive from fishing and local sources such as tourism and research activities. We discuss the potential impacts
of their presence on local fauna and some of the consequences on the Antarctic ecosystem. From this survey of plastic
accumulation in an ASPA, we propose the implementation of mitigation strategies, such as systematic monitoring of the
abundance and distribution of plastic waste, in order to identify trends in marine debris and control the levels of plastic pollution
in the Maritime Antarctic region.This work was supported by the Spanish Agencia Estatal de Investigación (AEI), Grant no. CTM2016-79741-R. PA is supported by a FPI-contract fellowship (Grant no. BES-2017 080558) from Spanish Ministerio de Economia y Competividad (MINECO)
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