83,714 research outputs found
Enhanced thermoelectric figure of merit in vertical graphene junctions
In this work, we investigate thermoelectric properties of junctions
consisting of two partially overlapped graphene sheets coupled to each other in
the cross-plane direction. It is shown that because of the weak van-der Waals
interactions between graphene layers, the phonon conductance in these junctions
is strongly reduced, compared to that of single graphene layer structures,
while their electrical performance is weakly affected. By exploiting this
effect, we demonstrate that the thermoelectric figure of merit can reach values
higher than 1 at room temperature in junctions made of gapped graphene
materials, for instance, graphene nanoribbons and graphene nanomeshes. The
dependence of thermoelectric properties on the junction length is also
discussed. This theoretical study hence suggests an efficient way to enhance
thermoelectric efficiency of graphene devices.Comment: 6 pages, 4 figures, submitte
Approximation by finite mixtures of continuous density functions that vanish at infinity
Given sufficiently many components, it is often cited that finite mixture
models can approximate any other probability density function (pdf) to an
arbitrary degree of accuracy. Unfortunately, the nature of this approximation
result is often left unclear. We prove that finite mixture models constructed
from pdfs in can be used to conduct approximation of various
classes of approximands in a number of different modes. That is, we prove
approximands in can be uniformly approximated, approximands
in can be uniformly approximated on compact sets, and
approximands in can be approximated with respect to the
, for . Furthermore, we also prove
that measurable functions can be approximated, almost everywhere
Intellectual Property and Antitrust Limits on Contract: Comment
In their chapter in Dynamic Competition and Public Policy (2001, Cambridge University Press), Burtis and Kobayashi never defined their model\u27s discount rate, making replicating their simulation results difficult. Through our own simulations, we were able to verify their results when using a discount rate of 0.10. We also identified two new types of equilibria that the authors overlooked, doubling the number of distinct equilibria in the model
Livestock CRP Vietnam 2019-2021 Site selection process
[The Livestock CRP can] focus on difficult regions with high poverty and ethnic minorities, showing how research can deliver impact in challenging area, but can also conduct active research in medium scale intensified livestock areas to address priority issues on market, feeds and forage, animal diseases, food safety, AMR and the environment. While poverty rates have reduced rapidly over the past decade at national level, there remain sizable pockets of poverty at regional level, particularly in North-West, Central Highlands and Mekong Delta regions. In these areas, livestock, particularly indigenous pigs and cattle, play an important livelihoods function and could raise household income if market access, productivity, and animal disease constraints are overcome. This suggests a need for a targeted, regional approach for livestockoriented research in Vietnam
Vietnam Inbound M&A Activity: the Role of Government Policy and Regulatory Environment
With a robust recent history of reform and opening, joining of the World Trade Organization, and negotiating a myriad of regional and global trade agreements, Vietnam has emerged as a promising destination for foreign direct investment(FDI) and cross-border mergers and acquisitions (M&A). In this paper, we providean overview of Vietnam’s inbound mergers and acquisitions and review the twomain driving forces of inbound M&A, which are the legal framework reformprocess and the equitization of State-owned enterprises. We close by providingdirections for future research in the area of cross-border M&As
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Improved Bar Impact Tests Using A Photonic Doppler Velocimeter
Bar impact tests, using the techniques described elsewhere in this symposium, were used to measure compressive and tensile strengths of borosilicate glass, soda lime glass, and a glass ceramic. The glass ceramic was 25% crystalline spinel, furnished by Corning Inc. There are two measures of compressive strength: the peak stress that can be transmitted in unconfined compression, and the >steady state> strength. For borosilicate glass and soda lime glass, these values were similar, being about 1.8 and 1.5 GPa, respectively. The glass ceramic (25% spinel) was almost 50% stronger. Tensile failure in the glass and glass ceramic takes places via surface flaws, and thus tensile strength is an extrinsic, as opposed to intrinsic property.Mechanical Engineerin
The trimer-based spin liquid candidate Ba4NbIr3O12
Ba4NbIr3O12, a previously unreported material with a triangular planar
geometry of Ir3O12 trimers, is described. Magnetic susceptibility measurements
show no magnetic ordering down to 1.8 K despite the Curie-Weiss temperature of
-13 K. The material has a very low effective magnetic moment of 0.80
{\mu}B/f.u. To look at the lower temperature behavior, the specific heat (Cp)
was measured down to 0.35 K; it shows no indication of magnetic ordering and
fitting a power law to Cp vs. T below 2 K yields the power {\alpha} = 3/4.
Comparison to the previously unreported trimer compound made with the 4d
element Rh in place of the 5d element Ir, Ba4NbRh3O12, is presented. The
analysis suggests that Ba4NbIr3O12 is a candidate spin liquid material.Comment: 19 pages, 7 main figures, 2 SI figure
Understanding requirements engineering process: a challenge for practice and education
Reviews of the state of the professional practice in Requirements Engineering (RE) stress that the RE process is both complex and hard to describe, and suggest there is a significant difference between competent and "approved" practice. "Approved" practice is reflected by (in all likelihood, in fact, has its genesis in) RE education, so that the knowledge and skills taught to students do not match the knowledge and skills required and applied by competent practitioners.
A new understanding of the RE process has emerged from our recent study. RE is revealed as inherently creative, involving cycles of building and major reconstruction of the models developed, significantly different from the systematic and smoothly incremental process generally described in the literature. The process is better characterised as highly creative, opportunistic and insight driven. This mismatch between approved and actual practice provides a challenge to RE education - RE requires insight and creativity as well as technical knowledge. Traditional learning models applied to RE focus, however, on notation and prescribed processes acquired through repetition. We argue that traditional learning models fail to support the learning required for RE and propose both a new model based on cognitive flexibility and a framework for RE education to support this model
Discontinuity of the Lempert function of the spectral ball
We give some further criteria for continuity or discontinuity of the Lempert
funtion of the spectral ball , with respect to one or both of its
arguments, in terms of cyclicity the matrices involved.Comment: 12 pages; the converse to theorem 1.3, mistakenly claimed in v1 & 2,
excised from v3, is now proved in some case
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