3,170 research outputs found
Smart control of an electric vehicle for ancillary service in DC microgrid
This article presents a two-stage framework for optimal Electric Vehicle (EV) charging/discharging strategy for DC Microgrid (MG) with Distributed Generators (DGs). A multi-objective optimisation task aimed at minimising system losses and EV battery degradation with Vehicle-to-Grid (V2G) peak shaving service has been realised. This coordinated EV integration into the DCMG was formulated as a directed weighted single source shortest path problem that was solved using a modified Dijkstra’s algorithm. The weights of the edges were obtained using primal-dual interior point method. The proposed framework has been experimentally verified using simulations with a test DCMG system with practical IEEE European low voltage test feeder load profiles. Results show realisation of peak demand shaving leveraging on EV discharge with minimal on-board battery degradation as well as reduced system losses. It is also shown that the proposed two-stage framework reduces the battery state of charge (SOC) sample space requirements in the analysis, thus, reducing the computational burden
Reducing Computational Complexity of Quantum Correlations
We address the issue of reducing the resource required to compute
information-theoretic quantum correlation measures like quantum discord and
quantum work deficit in two qubits and higher dimensional systems. We show that
determination of the quantum correlation measure is possible even if we utilize
a restricted set of local measurements. We find that the determination allows
us to obtain a closed form of quantum discord and quantum work deficit for
several classes of states, with a low error. We show that the computational
error caused by the constraint over the complete set of local measurements
reduces fast with an increase in the size of the restricted set, implying
usefulness of constrained optimization, especially with the increase of
dimensions. We perform quantitative analysis to investigate how the error
scales with the system size, taking into account a set of plausible
constructions of the constrained set. Carrying out a comparative study, we show
that the resource required to optimize quantum work deficit is usually higher
than that required for quantum discord. We also demonstrate that minimization
of quantum discord and quantum work deficit is easier in the case of two-qubit
mixed states of fixed ranks and with positive partial transpose in comparison
to the corresponding states having non-positive partial transpose. Applying the
methodology to quantum spin models, we show that the constrained optimization
can be used with advantage in analyzing such systems in quantum
information-theoretic language. For bound entangled states, we show that the
error is significantly low when the measurements correspond to the spin
observables along the three Cartesian coordinates, and thereby we obtain
expressions of quantum discord and quantum work deficit for these bound
entangled states.Comment: 19 pages, 14 figures, 3 table
Neutrino spin rotation in dense matter and electromagnetic field
Exact solutions of the Dirac--Pauli equation for massive neutrino with
anomalous magnetic moment interacting with dense matter and strong
electromagnetic field are found. The complete system of neutrino wavefunctions,
which show spin rotation properties are obtained and their possible
applications are discussed.Comment: 11 pages, latex, misprints are correcte
Charged Scalar Particles and Leptonic Decay
Charged scalar particles introduced in some extensions of the standard model
can induce leptonic decay at tree level. We find that with some charged
SU(2)-singlet scalar particles, like ones introduced in Zee-type models,
leptonic decay width is always smaller than what is predicted by the standard
model, therefore they may offer a natural solution to decay puzzle. To
be more specific, we examine some Zee-type models in detail to see if at the
same time they are acceptable in particle physics, cosmology and astrophysics.
It is shown that decay data do put some constrains on these models.Comment: ICTP Report No. IC/93/31, 12 pages, Latex, one figure is not
included, it is available upon deman
SN 2016coi/ASASSN-16fp: An example of residual helium in a type Ic supernova?
The optical observations of Ic-4 supernova (SN) 2016coi/ASASSN-16fp, from
to days after explosion, are presented along with analysis
of its physical properties. The SN shows the broad lines associated with SNe
Ic-3/4 but with a key difference. The early spectra display a strong absorption
feature at \AA\ which is not seen in other SNe~Ic-3/4 at this
epoch. This feature has been attributed to He I in the literature. Spectral
modelling of the SN in the early photospheric phase suggests the presence of
residual He in a C/O dominated shell. However, the behaviour of the He I lines
are unusual when compared with He-rich SNe, showing relatively low velocities
and weakening rather than strengthening over time. The SN is found to rise to
peak d after core-collapse reaching a bolometric luminosity of Lp
\ergs. Spectral models, including the nebular epoch, show
that the SN ejected \msun\ of material, with \msun\ below
5000 \kms, and with a kinetic energy of erg. The
explosion synthesised \msun\ of 56Ni. There are significant
uncertainties in E(B-V)host and the distance however, which will affect Lp and
MNi. SN 2016coi exploded in a host similar to the Large Magellanic Cloud (LMC)
and away from star-forming regions. The properties of the SN and the
host-galaxy suggest that the progenitor had of \msun\
and was stripped almost entirely down to its C/O core at explosion.Comment: Accepted for publication in MNRAS. Updated to reflect the published
version, minor typographical changes onl
Two-loop Radiative Neutrino Mechanism in an Gauge Model
By using the - - symmetry, we construct an
gauge model that provides two-loop radiative neutrino
masses as well as one-loop radiative neutrino masses. The generic smallness of
two-loop neutrino masses leading to compared with one-loop
neutrino masses leading to successfully explains by invoking the - -
breaking. The Higgs scalar () that initiates radiative mechanisms is
unified into a Higgs triplet together with the standard Higgs scalar (,
) to form (, , ), which calls for three families
of lepton triplets: (, , ) (i = 1,2,3), where
denote heavy neutral leptons. The two-loop radiative mechanism is
found possible by introducing a singly charged scalar, which couples to
(i,j = 2,3).Comment: with 10 pages, revtex, including 2 figures, accepted for publication
in Phys. Rev. D (with undefined latex citation indices removed
Phenomenology of Higgs bosons in the Zee-Model
To generate small neutrino masses radiatively, the Zee-model introduces two
Higgs doublets and one weak-singlet charged Higgs boson to its Higgs sector.
From analyzing the renormalization group equations, we determine the
possibile range of the lightest CP-even Higgs boson () mass and the Higgs
boson self-couplings as a function of the cut-off scale beyond which either
some of the coupling constants are strong enough to invalidate the perturbative
analysis or the stability of the electroweak vacuum is no longer guaranteed.
Using the results obtained from the above analysis, we find that the singlet
charged Higgs boson can significantly modify the partial decay width of via radiative corrections, and its collider phenomenology can
also be drastically different from that of the charged Higgs bosons in the
usual two-Higgs-doublet models.Comment: Added a paragraph and a figure in Section V, corrected typos, added
references. (RevTeX, 45 pages, 16 figures included.) To appear in Physical
Review
Electrochemical integration of graphene with light absorbing copper-based thin films
We present an electrochemical route for the integration of graphene with
light sensitive copper-based alloys used in optoelectronic applications.
Graphene grown using chemical vapor deposition (CVD) transferred to glass is
found to be a robust substrate on which photoconductive Cu_{x}S films of 1-2 um
thickness can be deposited. The effect of growth parameters on the morphology
and photoconductivity of Cu_{x}S films is presented. Current-voltage
characterization and photoconductivity decay experiments are performed with
graphene as one contact and silver epoxy as the other
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