161 research outputs found
ASEAN-EU university network programme on EMC and SI education
This paper reports about a project for the creation of an innovative university course devoted to the preparation of future electronic designers to the challenges imposed by the assurance of the electrical performance of high-speed electronic systems. The target groups are future university teaching staff and future electronic systems designers. Activities are developed by means of sharing research results, seminars, experience exchange and the development of demonstrators to be used for teaching. The partnership is composed by Technical University of Turin (Italy), University of Hannover (Germany), University of Nottingham (UK), Nanyang Technological University (Singapore) and King Monguts Institute of Technology Lad-krabang, Bangkok (Thailand). The program is partially funded by the European Commission under the ASEAN-EU University Network Programme (AUNP) and its duration is 24 months
High critical current densities in superconducting MgB2 thin films
Superconducting MgB2 thin films were prepared on Al2O3(0001) and MgO(100)
substrates. Boron thin films were deposited by the electron-beam evaporation
followed by post-annealing process with magnesium. Proper post annealing
conditions were investigated to grow good superconducting MgB2 thin films. The
X-ray diffraction patterns showed randomly orientated growth of MgB2 phase in
our thin films. The surface morphology was examined by scanning electron
microscope (SEM) and atomic force microscope (AFM). Critical current density
(Jc) measured by transport method was about 10^7 A/cm^2 at 15 K, and
superconducting transition temperature (Tc) was ~ 39 K in the MgB2 thin films
on Al2O3.Comment: 13 pages, 4 figures, submitted on Apr. 4, 2001, only one pdf fil
Generalized Phase Synchronization in unidirectionally coupled chaotic oscillators
We investigate phase synchronization between two identical or detuned
response oscillators coupled to a slightly different drive oscillator. Our
result is that phase synchronization can occur between response oscillators
when they are driven by correlated (but not identical) inputs from the drive
oscillator. We call this phenomenon Generalized Phase Synchronization (GPS) and
clarify its characteristics using Lyapunov exponents and phase difference
plots.Comment: 4 pages, 5 figure
A characterization of positive linear maps and criteria of entanglement for quantum states
Let and be (finite or infinite dimensional) complex Hilbert spaces. A
characterization of positive completely bounded normal linear maps from
into is given, which particularly gives a
characterization of positive elementary operators including all positive linear
maps between matrix algebras. This characterization is then applied give a
representation of quantum channels (operations) between infinite-dimensional
systems. A necessary and sufficient criterion of separability is give which
shows that a state on is separable if and only if
for all positive finite rank elementary operators
. Examples of NCP and indecomposable positive linear maps are given and
are used to recognize some entangled states that cannot be recognized by the
PPT criterion and the realignment criterion.Comment: 20 page
Narratives of ethnic identity among practitioners in community settings in the northeast of England
The increasing ethnic diversity of the UK has been mirrored by growing public awareness of multicultural issues, alongside developments in academic and government thinking. This paper explores the contested meanings around ethnic identity/ies in community settings, drawing on semi-structured interviews with staff from Childrenâs Centres and allied agencies conducted for a research project that examined the relationship between identity and the participation of parents/carers in services in northeast England. The research found that respondents were unclear about, especially, white ethnic identities, and commonly referred to other social categorizations, such as age, nationality, and circumstances such as mobility, when discussing service users. While in some cases this may have reflected legitimate attempts to resist overethnicizing non-ethnic phenomena, such constructions coexisted with assumptions about ethnic difference and how it might translate into service needs. These findings raise important considerations for policy and practice
BFFT formalism applied to the minimal chiral Schwinger model
We consider the minimal chiral Schwinger model, by embedding the gauge
noninvariant formulation into a gauge theory following the
Batalin-Fradkin-Fradkina-Tyutin point of view. Within the BFFT procedure, the
second class constraints are converted into strongly involutive first-class
ones, leading to an extended gauge invariant formulation. We also show that,
like the standard chiral model, in the minimal chiral model the Wess-Zumino
action can be obtained by performing a q-number gauge transformation into the
effective gauge noninvariant action.Comment: 11 Latex pages. Revised version: New section and more references
included. To appear in MPL
Dynamical mass generation of a two-component fermion in Maxwell-Chern-Simons QED_3: The lowest ladder approximation
Dynamical mass generation of a two-component fermion in with a
Chern-Simons term is investigated by solving the Schwinger-Dyson equation
formulated in the lowest ladder approximation. Dependence of the dynamical
fermion mass on a gauge-fixing parameter, a gauge coupling constant, and a
topological mass is examined by approximated analytical and also numerical
methods. The inclusion of the Chern-Simons term makes impossible to choose a
peculiar gauge in which a wave function renormalization is absent. The
numerical evaluation shows that the wave function renormalization is fairly
close to 1 in the Landau gauge. It means that this gauge is still a specific
gauge where the Ward-Takahashi identity is satisfied approximately. We also
find that the dynamical mass is almost constant if the topological mass is
larger than the coupling constant, while it decreases when the topological mass
is comparable to or smaller than the coupling constant and tends to the value
in without the Chern-Simons term.Comment: 22 pages, 9 figures, Version to appear in Phys. Rev.
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