1,093 research outputs found
Raising awareness for water polution based on game activities using internet of things
Awareness among young people regarding the environment and its resources and comprehension of the various factors that interplay, is key to changing human behaviour towards achieving a sustainable planet. In this paper IoT equipment, utilizing sensors for measuring various parameters of water quality, is used in an educational context targeting at a deeper understanding of the use of natural resources towards the adoption of environmentally friendly behaviours. We here note that the use of water sensors in STEM gameful learning is an area which has not received a lot of attention in the previous years. The IoT water sensing and related scenaria and practices, addressing children via discovery, gamification, and educational activities, are discussed in detail
Power loss estimation in the Electrostatic Separators of the ILC alternative head-on scheme at 500 GeV in the center-of-mass
This memo presents the power loss estimation in the Electrostatic Separators of the ILC alternative head-on scheme at 500 GeV in the center-of-mass, for the Nominal and High Luminosity beam parameters set, induced both by beam particles and radiative Bhabha processes
Construction of the probe beam photo-injector of CTF3
JACoW web site http://accelconf.web.cern.ch/AccelConf/e06This paper describes the HF (High-Frequency) and dynamic beam modelling performed onto the 3 GHz / 2,5 cells photo-injector of the future CTF3 (CLIC Test Facility 3) probe beam linac. The latter provides the beam to demonstrate the feasibility of the 30 GHz accelerating sections in the framework of the CLIC project. The Probe Beam Photo-Injector (PBPI) is inspired from the Drive Beam Photo-Injector (DBPI) already designed by LAL and actually tested in our laboratory. However, the design of PBPI has been simplified with respect to the previous because the charge per bunch is 4 times lower and the number of bunches several orders of magnitude smaller. The internal geometry and the coupling system of the PBPI have been designed with 2D (SUPERFISH*) and 3D (HFSS**) codes. Based on the modified design, PARMELA and POISSON simulations showed that the technical specifications are fulfilled. The vacuum issue has been also carefully investigated, and NEG (Non Evaporated Getter) technology has been adopted in order to reach the mbar pressure inside the structure. This work is done in deep collaboration with CEA/Saclay, which is responsible of the CTF3 Probe Beam Linac design and construction [1]
Skew-Product Decomposition of Planar Brownian Motion and Complementability
International audienceLet be a complex Brownian motion starting at 0 and the complex Brownian motion defined by . The natural filtration of is the filtration generated by up to an arbitrary rotation. We show that given any two different matrices and in , there exists an -previsible process taking values in such that the Brownian motion generates the whole filtration . As a consequence, for all and in such that , the Brownian motion is complementable in
Glassy freezing of orbital dynamics in FeCr2S4 and FeSc2S4
We report on a thorough dielectric investigation of the glass-like freezing
of the orbital reorientation-dynamics, recently found for the crystalline
sulpho-spinels FeCr2S4 and FeSc2S4. As the orbital reorientations are coupled
to a rearrangement of the surrounding ionic lattice via the Jahn-Teller effect,
the freezing of the orbital moments is revealed by a relaxational behaviour of
the complex dielectric permittivity. Additional conductivity (both dc and ac)
and contact contributions showing up in the spectra are taken into account by
an equivalent circuit description. The orbital relaxation dynamics continuously
slows down over six decades in time, before at the lowest temperatures the
glass transition becomes suppressed by quantum tunnelling.Comment: J. Non-Cryst. Solids, in press. 6 pages, 4 figure
Optical fabrication and characterisation of SU-8 disk photonic waveguide heterostructure cavities
In order to demonstrate cavity quantum electrodynamics using photonic crystal (PhC) cavities fabricated around self-assembled quantum dots (QDs), reliable spectral and spatial overlap between the cavity mode and the quantum dot is required. We present a method for using photoresist to optically fabricate heterostructure cavities in a PhC waveguide with a combined photolithography and micro-photoluminescence spectroscopy system. The system can identify single QDs with a spatial precision of ±25 nm, and we confirm the creation of high quality factor cavity modes deterministically placed with the same spatial precision. This method offers a promising route towards bright, on-chip single photon sources for quantum information applications
Superconducting pairing and density-wave instabilities in quasi-one-dimensional conductors
Using a renormalization group approach, we determine the phase diagram of an
extended quasi-one-dimensional electron gas model that includes interchain
hopping, nesting deviations and both intrachain and interchain repulsive
interactions. d-wave superconductivity, which dominates over the
spin-density-wave (SDW) phase at large nesting deviations, becomes unstable to
the benefit of a triplet -wave phase for a weak repulsive interchain
backscattering term , despite the persistence of dominant SDW
correlations in the normal state. Antiferromagnetism becomes unstable against
the formation of a charge-density-wave state when exceeds some
critical value. While these features persist when both Umklapp processes and
interchain forward scattering () are taken into account, the effect
of alone is found to frustrate nearest-neighbor interchain - and
-wave pairing and instead favor next-nearest-neighbor interchain singlet or
triplet pairing. We argue that the close proximity of SDW and
charge-density-wave phases, singlet d-wave and triplet -wave superconducting
phases in the theoretical phase diagram provides a possible explanation for
recent puzzling experimental findings in the Bechgaard salts, including the
coexistence of SDW and charge-density-wave phases and the possibility of a
triplet pairing in the superconducting phase.Comment: 19 pages, 13 figure
- …