3,173 research outputs found
Initial characterization of an Experimental Referee Broadened-Specification (ERBS) aviation turbine fuel
Characterization data and a hydrocarbon compositional analysis are presented for a research test fuel designated as an experimental referee broadened-specification aviation turbine fuel. This research fuel, which is a special blend of kerosene and hydrotreated catalytic gas oil, is a hypothetical representation of a future fuel should it become necessary to broaden current kerojet specifications. It is used as a reference fuel in research investigations into the effects of fuel property variations on the performance and durability of jet aircraft components, including combustors and fuel systems
Phenomenology of The Left-Right Twin Higgs Model
The twin Higgs mechanism has recently been proposed to solve the little
hierarchy problem. We study the implementation of the twin Higgs mechanism in
left-right models. At TeV scale, heavy quark and gauge bosons appear, with rich
collider phenomenology. In addition, there are extra Higgses, some of which
couple to both the Standard Model fermion sector and the gauge sector, while
others couple to the gauge bosons only. We present the particle spectrum, and
study the general features of the collider phenomenology of this class of model
at the Large Hadron Collider.Comment: 41 pages, version appears in PR
Financial social accounting matrix: concepts, constructions and theoretical framework
A Social Accounting Matrix (hereafter, SAM) is a particular tool to represent that whole economic activities incomes and expenditures flows accounts through a socio-economic system, which captures the transactions and transfers between all economic agents and institutions in the system. During the last two decades, the financial market are well developed and significantly impacts the economic growth, it will be more worthy to move from a real SAM to a Financial SAM, containing the details of the financial institutions and transaction of agents’ assets and liabilities. Therefore, this paper will discuss the outlines and constructions framework for the aggregate Financial SAM. The understanding of the structure of Financial SAM can be a database for a financial Computed General Equilibrium (CGE) model and can be used to analyze the behavior of national’s public debt.SOCIAL ACCOUNTING MATRIX (SAM), FINANCIAL, FLOW-OF-FUNDS
Electrical modulation of the edge channel transport in topological insulators coupled to ferromagnetic leads
The counterpropagating edge states of a two-dimensional topological insulator
(TI) carry electrons of opposite spins. We investigate the transport properties
of edge states in a two-dimensional TI which is contacted to ferromagnetic
leads. The application of a side-gate voltage induces a constriction or quantum
point contact (QPC) which couples the two edge channels. The transport
properties of the system is calculated via the Keldysh nonequilibrium Green's
function method. We found that inter-edge spin-flip coupling can significantly
enhance (suppress) the charge current when the magnetization of the leads are
anti-parallel (parallel) to one another. On the other hand, spin-conserving
inter-edge coupling generally reduces the current by backscattering regardless
of the magnetization configuration. The charge current and the conductance as a
function of the bias voltage, also exhibit similar trends with respect to
spin-flip coupling strength, for both parallel and anti-parallel
configurations. Hence, gate voltage modulation of edge states via a QPC can
provide a means of modulating the spin or charge current flow in TI-based
spintronics devices.Comment: 6 pages, 3 figures, submitted to J. Appl. Phy
Socioeconomics and values of resources in great Lake-Tonle Sap and Mekong-Bassac area : results from a sample survey in Kampong Chhnang, Siem Reap and Kandal provinces, Cambodia
Socioeconomics aspects, Fishery economics, Cambodia,
Transmission channels for light in absorbing random media: from diffusive to ballistic-like transport
While the absorption of light is ubiquitous in nature and in applications,
the question remains how absorption modifies the transmission channels in
random media. We present a numerical study on the effects of optical absorption
on the maximal transmission and minimal reflection channels in a
two-dimensional disordered waveguide. In the weak absorption regime, where the
system length is less than the diffusive absorption length, the maximal
transmission channel is dominated by diffusive transport and it is equivalent
to the minimal reflection channel. Its frequency bandwidth is determined by the
underlying quasimode width. However, when the absorption is strong, light
transport in the maximal transmission channel undergoes a sharp transition and
becomes ballistic-like transport. Its frequency bandwidth increases with
absorption, and the exact scaling varies with the sample's realization. The
minimal reflection channel becomes different from the maximal transmission
channel and becomes dominated by absorption. Counterintuitively, we observe in
some samples that the minimum reflection eigenvalue increases with absorption.
Our results show that strong absorption turns open channels in random media
from diffusive to ballistic-like.Comment: 11 pages, 7 figure
Research on aviation fuel instability
The underlying causes of fuel thermal degradation are discussed. Topics covered include: nature of fuel instability and its temperature dependence, methods of measuring the instability, chemical mechanisms involved in deposit formation, and instrumental methods for characterizing fuel deposits. Finally, some preliminary thoughts on design approaches for minimizing the effects of lowered thermal stability are briefly discussed
Coherent control of photocurrent in a strongly scattering photoelectrochemical system
A fundamental issue that limits the efficiency of many photoelectrochemical
systems is that the photon absorption length is typically much longer than the
electron diffusion length. Various photon management schemes have been
developed to enhance light absorption; one simple approach is to use randomly
scattering media to enable broadband and wide-angle enhancement. However, such
systems are often opaque, making it difficult to probe photo-induced processes.
Here we use wave interference effects to modify the spatial distribution of
light inside a highly-scattering dye-sensitized solar cell to control photon
absorption in a space-dependent manner. By shaping the incident wavefront of a
laser beam, we enhance or suppress photocurrent by increasing or decreasing
light concentration on the front side of the mesoporous photoanode where the
collection efficiency of photoelectrons is maximal. Enhanced light absorption
is achieved by reducing reflection through the open boundary of the photoanode
via destructive interference, leading to a factor of two increase in
photocurrent. This approach opens the door to probing and manipulating
photoelectrochemical processes in specific regions inside nominally opaque
media.Comment: 21 pages, 4 figures, in submission. The first two authors contributed
equally to this paper, and should be regarded as co-first author
Critical Fidelity
Using a Wigner Lorentzian Random Matrix ensemble, we study the fidelity,
, of systems at the Anderson metal-insulator transition, subject to small
perturbations that preserve the criticality. We find that there are three decay
regimes as perturbation strength increases: the first two are associated with a
gaussian and an exponential decay respectively and can be described using
Linear Response Theory. For stronger perturbations decays algebraically
as , where is the correlation dimension of the
critical eigenstates.Comment: 4 pages, 3 figures. Revised and published in Phys. Rev. Let
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