15,834 research outputs found
How to add a boundary condition
Given a conformal QFT local net of von Neumann algebras B_2 on the
two-dimensional Minkowski spacetime with irreducible subnet A\otimes\A, where A
is a completely rational net on the left/right light-ray, we show how to
consistently add a boundary to B_2: we provide a procedure to construct a
Boundary CFT net B of von Neumann algebras on the half-plane x>0, associated
with A, and locally isomorphic to B_2. All such locally isomorphic Boundary CFT
nets arise in this way. There are only finitely many locally isomorphic
Boundary CFT nets and we get them all together. In essence, we show how to
directly redefine the C* representation of the restriction of B_2 to the
half-plane by means of subfactors and local conformal nets of von Neumann
algebras on S^1.Comment: 20 page
Experimental Investigation of FastâCharging Effect on Aging of Electric Vehicle LiâIon Batteries
A huge increase in fastâcharging stations will be necessary for the transition to EVs. Nevertheless, charging a battery pack at a higher Cârate impacts its state of health, accelerating its degradation. The present paper proposes a different and innovative approach that considers the daily routine of an EV Liâion battery based on a standard driving cycle, including charging phases when the depth of discharge is 90%. Through dynamic modeling of the EV battery system, the state of charge evolution is determined for different charging Cârates, considering both real discharging and charging current profiles. Finally, by applying a suitable postâprocessing procedure, aging test features are defined, each being related to a specific EV battery working mode, including charging at a particular Cârate, considering the global battery operation during its lifespan. It is demonstrated that, according to the implemented procedure, fastâcharging cycles at 50 kW reduce battery lifespan by about 17% with respect to charge in a 22 kW threeâphase AC column, in parity with the discharge rate. Thus, this work can provide a deep insight into the expected massive penetration of electric vehicles, providing an estimate of battery useful life based on charging conditions
Some computations in the cyclic permutations of completely rational nets
In this paper we calculate certain chiral quantities from the cyclic
permutation orbifold of a general completely rational net. We determine the
fusion of a fundamental soliton, and by suitably modified arguments of A. Coste
, T. Gannon and especially P. Bantay to our setting we are able to prove a
number of arithmetic properties including congruence subgroup properties for
matrices of a completely rational net defined by K.-H. Rehren .Comment: 30 Pages Late
Evidence of a pressure-induced metallization process in monoclinic VO
Raman and combined trasmission and reflectivity mid infrared measurements
have been carried out on monoclinic VO at room temperature over the 0-19
GPa and 0-14 GPa pressure ranges, respectively. The pressure dependence
obtained for both lattice dynamics and optical gap shows a remarkable stability
of the system up to P*10 GPa. Evidence of subtle modifications of V ion
arrangements within the monoclinic lattice together with the onset of a
metallization process via band gap filling are observed for PP*. Differently
from ambient pressure, where the VO metal phase is found only in
conjunction with the rutile structure above 340 K, a new room temperature
metallic phase coupled to a monoclinic structure appears accessible in the high
pressure regime, thus opening to new important queries on the physics of
VO.Comment: 5 pages, 3 figure
On The Use Of Polyurethane Matrix Carbon Fiber Composites For Strengthening Concrete Structures
Fiber-reinforced polymer (FRP) composite materials have effectively been used in numerous reinforced concrete civil infrastructure strengthening projects. Although a significant body of knowledge has been established for epoxy matrix carbon FRPs and epoxy adhesives, there is still a need to investigate other matrices and adhesive types. One such matrix/adhesive type yet to be heavily researched for infrastructure application is polyurethane. This thesis investigates use of polyurethane matrix carbon fiber composites for strengthening reinforced concrete civil infrastructure. Investigations on mirco- and macro-mechanical composite performance, strengthened member flexural performance, and bond durability under environmental conditioning will be presented. Results indicate that polyurethane carbon composites could potentially be a viable option for strengthening concrete structures
Fermi LAT Gamma-ray Detections of Classical Novae V1369 Centauri 2013 and V5668 Sagittarii 2015
We report the Fermi Large Area Telescope (LAT) detections of high-energy
(>100 MeV) gamma-ray emission from two recent optically bright classical novae,
V1369 Centauri 2013 and V5668 Sagittarii 2015. At early times, Fermi
target-of-opportunity observations prompted by their optical discoveries
provided enhanced LAT exposure that enabled the detections of gamma-ray onsets
beginning ~2 days after their first optical peaks. Significant gamma-ray
emission was found extending to 39-55 days after their initial LAT detections,
with systematically fainter and longer duration emission compared to previous
gamma-ray detected classical novae. These novae were distinguished by multiple
bright optical peaks that encompassed the timespans of the observed gamma rays.
The gamma-ray light curves and spectra of the two novae are presented along
with representative hadronic and leptonic models, and comparisons to other
novae detected by the LAT are discussed.Comment: 13 pages, 6 figures, 4 tables, ApJ accepte
A multi-layer edge-on single photon counting silicon microstrip detector for innovative techniques in diagnostic radiology
A three-layer detector prototype, obtained by stacking three edge-on single photon counting silicon microstrip detectors, has been developed and widely tested. This was done in the framework of the Synchrotron Radiation for Medical Physics/Frontier Radiology (SYRMEP/FRONTRAD) collaboration activities, whose aim is to improve the quality of mammographic examinations operating both on the source and on the detector side. The active surface of the device has been fully characterized making use of an edge-scanning technique and of a well-collimated laminar synchrotron radiation beam. The obtained data (interlayer distances, channel correspondence, etc.) have then been used to combine information coming from each detector layer, without causing any loss in spatial and contrast resolution of the device. Contrast and spatial resolution have also been separately evaluated for each detector layer. Moreover, imaging techniques (phase contrast, refraction, and scatter imaging), resulting in an increased visibility of low absorbing details, have been implemented, and their effectiveness has been tested on a biological sample. Finally, the possibility of simultaneously acquiring different kind of images with the different detector layers is discussed. This would result in maximizing the information extracted from the sample, while at the same time the high absorption efficiency of the detector device would allow a low dose delivery
Algebraic conformal quantum field theory in perspective
Conformal quantum field theory is reviewed in the perspective of Axiomatic,
notably Algebraic QFT. This theory is particularly developped in two spacetime
dimensions, where many rigorous constructions are possible, as well as some
complete classifications. The structural insights, analytical methods and
constructive tools are expected to be useful also for four-dimensional QFT.Comment: Review paper, 40 pages. v2: minor changes and references added, so as
to match published versio
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