2,764 research outputs found
GEL: Exploring Game Enhanced Learning
AbstractA brief presentation is given of the objectives and activities pursed in GEL (Game Enhanced Learning), a Theme Team initiative financed by the STELLAR Network of Excellence in Technology Enhanced Learning (TEL) during year 2011 - 2012. Some of GEL's main outputs relevant to the Serious Games research field are also outlined
Serious Games in Formal Education: Discussing Some Critical Aspects
International audienceInnovation in technology together with evolution in pedagogical approaches is encouraging increased integration of technology-supported interventions in mainstream teaching practices. One area attracting particularly close attention in this respect is Serious Games (SGs), which offer considerable potential for facilitating both formal and informal learning experiences in supported and standalone contexts. Advances in technology and in technology enhanced learning are raising learners' expectations for immersive and engaging game-based experiences. This trend is underpinned by the emergence of young learners adept at using digital technologies and the internet; there is an attendant risk that, as students, they may be alienated by traditional education and its failure to engage them fully in a lifelong learning process and prepare them adequately for the challenges of the 21st Century. SGs would appear to offer an attractive solution in this regard. However, there are a number of inhibitors preventing their wider take-up in mainstream education, with the result that the considerable potential on offer has yet to be fully exploited. This situation is the background for the joint efforts of partners in the Games and Learning Alliance (GALA), an EC-funded Network of Excellence on SGs, especially the sub-group dedicated to the pedagogical dimension of SGs. In its discussions on the key challenges for more wide-scale and effective SG use, the group has focused in particular on aspects related to the central role played by the educator in formal education settings. Specifically, discussion has focused on the challenges posed when educators are called on to modify their practice, adopting the new roles and approaches demanded for effective SG deployment. This paper presents the outcome of the group's exploration. It frames the question of the educator's central role by drawing on research work that, in the view of the different authors, embodies the major references for shedding light on this multi-faceted aspect. As well as the new role that the educator assumes in games-based learning environments, particular attention is also dedicated to the innovative pedagogical approaches that can be applied to SG deployment, especially those inspired by peer collaboration
Temperature dependence of the spectral weight in p- and n-type cuprates: a study of normal state partial gaps and electronic kinetic energy
The optical conductivity of CuO2 (copper-oxygen) planes in p- and n-type
cuprates thin films at various doping levels is deduced from highly accurate
reflectivity data. The temperature dependence of the real part sigma1(omega) of
this optical conductivity and the corresponding spectral weight allow to track
the opening of a partial gap in the normal state of n-type Pr{2-x}Ce(x)CuO4
(PCCO), but not of p-type Bi2Sr2CaCu2O(8+delta} (BSCCO) cuprates. This is a
clear difference between these two families of cuprates, which we briefly
discuss. In BSCCO, the change of the electronic kinetic energy Ekin - deduced
from the spectral weight- at the superconducting transition is found to cross
over from a conventional BCS behavior (increase of Ekin below Tc to an
unconventional behavior (decrease of Ekin below Tc) as the free carrier density
decreases. This behavior appears to be linked to the energy scale over which
spectral weight is lost and goes into the superfluid condensate, hence may be
related to Mott physics
Top-transmon: hybrid superconducting qubit for parity-protected quantum computation
Qubits constructed from uncoupled Majorana fermions are protected from
decoherence, but to perform a quantum computation this topological protection
needs to be broken. Parity-protected quantum computation breaks the protection
in a minimally invasive way, by coupling directly to the fermion parity of the
system --- irrespective of any quasiparticle excitations. Here we propose to
use a superconducting charge qubit in a transmission line resonator (a socalled
transmon) to perform parity-protected rotations and read-out of a topological
(top) qubit. The advantage over an earlier proposal using a flux qubit is that
the coupling can be switched on and off with exponential accuracy, promising a
reduced sensitivity to charge noise.Comment: 7 pages, 5 figure
Influence of Irradiance, Flow Rate, Reactor Geometry, and Photopromoter Concentration in Mineralization Kinetics of Methane in Air and in Aqueous Solutions by Photocatalytic Membranes Immobilizing Titanium Dioxide
Photomineralization of methane in air (10.0–1000 ppm (mass/volume) of C) at100%relative humidity (dioxygen as oxygen donor) was systematically studied at318±3 K in an annular laboratory-scale reactor by photocatalytic membranes immobilizing titanium dioxide as a function of substrate concentration, absorbed power per unit length of membrane, reactor geometry, and concentration of a proprietary vanadium alkoxide as photopromoter. Kinetics of both substrate disappearance, to yield intermediates, and total organic carbon (TOC) disappearance, to yield carbon dioxide, were followed. At a fixed value of irradiance (0.30 W⋅cm-1), the mineralization experiments in gaseous phase were repeated as a function of flow rate (4–400 m3⋅h−1). Moreover, at a standard flow rate of 300 m3⋅h−1, the ratio between the overall reaction volume and the length of the membrane was varied, substantially by varying the volume of reservoir, from and to which circulation of gaseous stream took place. Photomineralization of methane in aqueous solutions was also studied, in the same annular reactor and in the same conditions, but in a concentration range of 0.8–2.0 ppm of C, and by using stoichiometric hydrogen peroxide as an oxygen donor. A kinetic model was employed, from which, by a set of differential equations, four final optimised parameters,k1andK1,k2andK2, were calculated, which is able to fit the whole kinetic profile adequately. The influence of irradiance onk1andk2, as well as of flow rate onK1andK2, is rationalized. The influence of reactor geometry onkvalues is discussed in view of standardization procedures of photocatalytic experiments. Modeling of quantum yields, as a function of substrate concentration and irradiance, as well as of concentration of photopromoter, was carried out very satisfactorily. Kinetics of hydroxyl radicals reacting between themselves, leading to hydrogen peroxide, other than with substrate or intermediates leading to mineralization, were considered, and it is paralleled by a second competition kinetics involving superoxide radical anion
Inflammation in sputum relates to progression of disease in subjects with COPD: a prospective descriptive study
BACKGROUND: Inflammation is considered to be of primary pathogenic importance in COPD but the evidence on which current understanding is based does not distinguish between cause and effect, and no single mechanism can account for the complex pathology. We performed a prospective longitudinal study of subjects with COPD that related markers of sputum inflammation at baseline to subsequent disease progression. METHODS: A cohort of 56 patients with chronic bronchitis was characterized in the stable state at baseline and after an interval of four years, using physiological measures and CT densitometry. Sputum markers of airway inflammation were quantified at baseline from spontaneously produced sputum in a sub-group (n = 38), and inflammation severity was related to subsequent disease progression. RESULTS: Physiological and CT measures indicated disease progression in the whole group. In the sub-group, sputum myeloperoxidase correlated with decline in FEV(1 )(rs = -0.344, p = 0.019, n = 37). LTB4 and albumin leakage correlated with TLCO decline (rs = -0.310, p = 0.033, rs = -0.401, p = 0.008, respectively, n = 35) and IL-8 correlated with progression of lung densitometric indices (rs = -0.464, p = 0.005, n = 38). CONCLUSION: The data support a principal causative role for neutrophilic inflammation in the pathogenesis of COPD and suggest that the measurement of sputum inflammatory markers may have a predictive role in clinical practice
Proton-air cross section measurement with the ARGO-YBJ cosmic ray experiment
The proton-air cross section in the energy range 1-100 TeV has been measured
by the ARGO-YBJ cosmic ray experiment. The analysis is based on the flux
attenuation for different atmospheric depths (i.e. zenith angles) and exploits
the detector capabilities of selecting the shower development stage by means of
hit multiplicity, density and lateral profile measurements at ground. The
effects of shower fluctuations, the contribution of heavier primaries and the
uncertainties of the hadronic interaction models, have been taken into account.
The results have been used to estimate the total proton-proton cross section at
center of mass energies between 70 and 500 GeV, where no accelerator data are
currently available.Comment: 14 pages, 9 figure
Laboratory-scale photomineralization of n-alkanes in gaseous phase by photocatalytic membranes immobilizing titanium dioxide
Kinetics of photocatalytic oxidation of methane, ethane, and n-heptane, to yield intermediates, and photomineralization of intermediates, to yield carbon dioxide and water, was studied in the gaseous phase, at 308 +/- 2 K, by a laboratory-scale photoreactor and photocatalytic membranes immobilizing 30 +/- 3wt.% of TiO2, in the presence of aerosolized stoichiometric hydrogen peroxide as oxygen donor, and at a relative humidity close to 100%. The whole volume of irradiated solution was 4.000 +/- 0.005 L, the ratio between this volume and the geometrical apparent surface of the irradiated side of the photocatalytic membrane was 3.8 +/- 0.1 cm, and the absorbed power was 0.30 W/cm ( cylindrical geometry). The pinetic parameters of the present work substantially coincide with those of the same molecules previously studied in aqueous solution, within the limits of experimental uncertainty. Photocatalytic processes thus appear to be controlled by interface phenomena, which are ruled kinetically, and apparently also thermodynamically, by concentration gradients, independently on diffusion and other processes in the aqueous or gaseous bulk, if turbulence in these phases is adequately assured
High Altitude test of RPCs for the ARGO-YBJ experiment
A 50 m**2 RPC carpet was operated at the YangBaJing Cosmic Ray Laboratory
(Tibet) located 4300 m a.s.l. The performance of RPCs in detecting Extensive
Air Showers was studied. Efficiency and time resolution measurements at the
pressure and temperature conditions typical of high mountain laboratories, are
reported.Comment: 16 pages, 10 figures, submitted to Nucl. Instr. Met
Gamma ray flares from Mrk421 in 2008 observed with the ARGO-YBJ detector
In 2008 the blazar Markarian 421 entered a very active phase and was one of
the brightest sources in the sky at TeV energies, showing frequent flaring
episodes. Using the data of ARGO-YBJ, a full coverage air shower detector
located at Yangbajing (4300 m a.s.l., Tibet, China), we monitored the source at
gamma ray energies E > 0.3 TeV during the whole year. The observed flux was
variable, with the strongest flares in March and June, in correlation with
X-ray enhanced activity. While during specific episodes the TeV flux could be
several times larger than the Crab Nebula one, the average emission from day 41
to 180 was almost twice the Crab level, with an integral flux of (3.6 +-0.6)
10^-11 photons cm^-2 s^-1 for energies E > 1 TeV, and decreased afterwards.
This paper concentrates on the flares occurred in the first half of June.
This period has been deeply studied from optical to 100 MeV gamma rays, and
partially up to TeV energies, since the moonlight hampered the Cherenkov
telescope observations during the most intense part of the emission. Our data
complete these observations, with the detection of a signal with a statistical
significance of 3.8 standard deviations on June 11-13, corresponding to a gamma
ray flux about 6 times larger than the Crab one above 1 TeV. The reconstructed
differential spectrum, corrected for the intergalactic absorption, can be
represented by a power law with an index alpha = -2.1 extending up to several
TeV. The spectrum slope is fully consistent with previous observations
reporting a correlation between the flux and the spectral index, suggesting
that this property is maintained in different epochs and characterizes the
source emission processes.Comment: Accepted for publication on ApJ
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