5,480 research outputs found
Graphene field-effect transistors based on boron nitride gate dielectrics
Graphene field-effect transistors are fabricated utilizing single-crystal
hexagonal boron nitride (h-BN), an insulating isomorph of graphene, as the gate
dielectric. The devices exhibit mobility values exceeding 10,000 cm2/V-sec and
current saturation down to 500 nm channel lengths with intrinsic
transconductance values above 400 mS/mm. The work demonstrates the favorable
properties of using h-BN as a gate dielectric for graphene FETs.Comment: 4 pages, 8 figure
Space suit
A pressure suit for high altitude flights, particularly space missions is reported. The suit is designed for astronauts in the Apollo space program and may be worn both inside and outside a space vehicle, as well as on the lunar surface. It comprises an integrated assembly of inner comfort liner, intermediate pressure garment, and outer thermal protective garment with removable helmet, and gloves. The pressure garment comprises an inner convoluted sealing bladder and outer fabric restraint to which are attached a plurality of cable restraint assemblies. It provides versitility in combination with improved sealing and increased mobility for internal pressures suitable for life support in the near vacuum of outer space
Electronic compressibility of layer polarized bilayer graphene
We report on a capacitance study of dual gated bilayer graphene. The measured
capacitance allows us to probe the electronic compressibility as a function of
carrier density, temperature, and applied perpendicular electrical displacement
D. As a band gap is induced with increasing D, the compressibility minimum at
charge neutrality becomes deeper but remains finite, suggesting the presence of
localized states within the energy gap. Temperature dependent capacitance
measurements show that compressibility is sensitive to the intrinsic band gap.
For large displacements, an additional peak appears in the compressibility as a
function of density, corresponding to the presence of a 1-dimensional van Hove
singularity (vHs) at the band edge arising from the quartic bilayer graphene
band structure. For D > 0, the additional peak is observed only for electrons,
while D < 0 the peak appears only for holes. This asymmetry that can be
understood in terms of the finite interlayer separation and may be useful as a
direct probe of the layer polarization
Research on Long-Term Care Homes for Older People in Brazil: Protocol for Scoping Review
LOTUS CONSORTIUM - Improving care in Long-term Care Institutions in Brazil and Europe through Collaboration and ResearchBackground
The fast growth of the ageing population in low and middle-income countries, such as Brazil, has allowed little time for social and health care systems to adapt. As the care needs for the most vulnerable and frail older people become increasingly complex, services and governments need to ensure that long term care homes deliver high-quality and evidence-based care to meet their healthcare needs.
Aim
To examine and map the range of research undertaken in Brazil regarding care homes published in peer reviewed journals.
Method
This scoping review will consider all relevant peer-reviewed primary studies fully or partly conducted in Brazilian care homes including those which consider workforce (for example, e.g. healthcare professionals, care staff, and management level staff) and care home residents (older people aged 60 years and above), using empirical and original research focused on any health related topic. The searches will be conducted using bibliographic databases (MEDLINE, EMBASE, LILACS and Google Scholar) and manual searching of the reference lists of relevant studies published in English, Portuguese or Spanish from inception up to 2018. Two authors will independently screen each document by title and abstract against the eligibility criteria. In case of disagreement, a third reviewer will be consulted. Data from the included studies will be extracted and reported using tables, graphs, and narrative accounts using elements of content analysis. The Mixed Methods Appraisal Tool will be used to appraise the methodological quality of the included studies
C4 olefin conversion on reduced nickel y faujasite. Evidence for C5 olefin formation via C4 olefin disproportionation
Novel Methods for Determining Effective Interactions for the Nuclear Shell Model
The Contractor Renormalization (CORE) method is applied in combination with
modern effective-theory techniques to the nuclear many-body problem. A
one-dimensional--yet ``realistic''--nucleon-nucleon potential is introduced to
test these novel ideas. It is found that the magnitude of ``model-space''
(CORE) corrections diminishes considerably when an effective potential that
eliminates the hard-momentum components of the potential is first introduced.
As a result, accurate predictions for the ground-state energy of the there-body
system are made with relatively little computational effort when both
techniques are used in a complementary fashion.Comment: 14 pages, 5 figures and 2 tabl
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Computational chemistry on parallel computers
The recent successful adaptation of mainline computational chemistry codes to parallel computers introduces a new era of cost-effective, computer-intensive chemistry applications and paves the way for future applications on massively parallel centralized computers being developed under the High Performance Computer and Communications Initiative. Parallel computer architecture offers the promise of inexpensive supercomputing for the price of effort in algorithm adaptations to parallelism. In Chemical Sciences-supported work at Argonne, beginning efforts at algorithm changes in computational chemistry codes has resulted in program performances on the Group`s 12-processor Alliant computer superior to that on one-processor Cray X-MP or Y-MP computers. The effort so far has focused on sophisticated and highly accurate electronic structure production codes for determining the forces between atoms and molecules responsible for chemical structure, spectra, and reactivity. Some effort has also been invested in trajectory simulations of molecular dynamics. The American-made Alliant computer (model FX/2812) is one of the latest generation of shared-memory group- or division-size computers that generally cost about an order of magnitude less than the laboratory- or university-size computers such as Crays
Measuring Relations Between Concepts In Conceptual Spaces
The highly influential framework of conceptual spaces provides a geometric
way of representing knowledge. Instances are represented by points in a
high-dimensional space and concepts are represented by regions in this space.
Our recent mathematical formalization of this framework is capable of
representing correlations between different domains in a geometric way. In this
paper, we extend our formalization by providing quantitative mathematical
definitions for the notions of concept size, subsethood, implication,
similarity, and betweenness. This considerably increases the representational
power of our formalization by introducing measurable ways of describing
relations between concepts.Comment: Accepted at SGAI 2017 (http://www.bcs-sgai.org/ai2017/). The final
publication is available at Springer via
https://doi.org/10.1007/978-3-319-71078-5_7. arXiv admin note: substantial
text overlap with arXiv:1707.05165, arXiv:1706.0636
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