1,755 research outputs found
Atmospheric muon background in the ANTARES detector
An evaluation of the background due to atmospheric muons in the ANTARES high
energy neutrino telescope is presented. Two different codes for atmospheric
shower simulation have been used. Results from comparisons between these codes
at sea level and detector level are presented. The first results on the
capability of ANTARES to reject this class of background are given.Comment: 4 pages, 4 figures, To appear in Proceedings of the 29th
International Cosmic Ray Conference (ICRC 2005), Pune, India, 3 - 10 Aug 200
Meaurement of Cosmic Ray elemental composition from the CAKE balloon experiment
CAKE (Cosmic Abundances below Knee Energies) was a prototype balloon
experiment for the determination of the charge spectra and of abundances of the
primary cosmic-rays (CR) with Z10. It was a passive instrument made of
layers of CR39 and Lexan nuclear track detectors; it had a geometric acceptance
of 0.7 msr for Fe nuclei. Here, the scanning and analysis strategies,
the algorithms used for the off-line filtering and for the tracking in
automated mode of the primary cosmic rays are presented, together with the
resulting CR charge distribution and their abundances.Comment: 5 pages, 8 figure
Nuclear Track Detectors for Environmental Studies and Radiation Monitoring
Several improvements were made for Nuclear Track Detectors (NTDs) used for
environmental studies and for particle searches. A new method was used to
determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the
simultaneous measurement of the diameter and of the height of etch-pit cones
caused by relativistic heavy ions (158 A GeV Pb(82+) and In(49+) ions) and
their fragments. The use of alcohol in the etching solution improves the
surface quality of NTDs and it raises their thresholds. The detectors were used
for the determination of nuclear fragmentation cross sections of Iron and
Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for
the determination of doses in hadron therapy and for doses received by
astronauts. The detectors were also used in the search of massive particles in
the cosmic radiation, for the determination of the mass spectrum of cosmic rays
and for the evaluation of Po(210) alpha decay and of natural radon
concentrations.Comment: 7 pages, 5 EPS figures. Presented at the 10th Topical Seminar on
Innovative Particle and Radiation Detectors, 1-5 October 2006, Siena, Ital
Social capital and rural innovation process. The evaluation of the measure 124 \u201cCooperation for Development of New Products, Processes and Technologies in the Agriculture, Food and Forestry Sector\u201d in the Umbria Region (Italy)
The most recent theories on innovation point out the role of social networks, demonstrating how knowledge is intertwined with network communities and social capital represents an essential factor to comprehend innovation. The social network dimension of the innovation process is also acknowledged in the actual definition of an agricultural innovation system (AIS). This study attempts to assess the role played by social capital in agricultural innovation projects co-financed by the Measure 124 of the Rural Development Program (2007-2013) of the Umbria Region (Italy), based on the analysis of 5 evaluation criteria (relevance, innovation, effectiveness, sustainability, and social capital) in relation to 8 selected projects. The obtained results confirm the validity of the proposed methodology both for the purpose of internal monitoring of the project and for the assessment of the measure on the basis of tangible and intangible factors, such as social capital
Bulk Etch Rate Measurements and Calibrations of Plastic Nuclear Track Detectors
New calibrations of CR39 and Makrofol nuclear track detectors have been
obtained using 158 A GeV Pb (82+) and In (49+) ions; a new method for the bulk
etch rate determination, using both cone height and base diameter measurements
was developed. The CR39 charge resolution based on the etch-pit base area
measurement is adequate to identify nuclear fragments in the interval 7 <=
Z/beta <= 49. For CR39 the detection threshold is at REL~50 MeV cm^2/g,
corresponding to a nuclear fragment with Z/beta~7. Base cone area distributions
for Makrofol foils exposed to Pb (82+) ions have shown for the first time all
peaks due to nuclear fragments with Z > 50; the distribution of the etched cone
heights shows well separated individual peaks for Z/beta = 78 - 83 (charge
pickup). The Makrofol detection threshold is at REL 2700 MeV cm^2/g,
corresponding to a nuclear fragment with Z/beta~50.Comment: 11 pages, 5 EPS figures. Submitted to Nucl. Instr. Meth.
Collaborative facilitation and collaborative inhibition in virtual environments
Worldwide, organizations and small and medium-sized enterprises have already disruptively changed in many ways their physiological inner mechanisms, because of information and communication technologies (ICT) revolution. Nevertheless, the still ongoing COVID-19 worldwide emergency definitely promoted a wide adoption of teleworking modalities for many people around the world, making it more relevant than before to understand the real impact of virtual environments (VEs) on teamwork dynamics. From a psychological point of view, a critical question about teleworking modalities is how the social and cognitive dynamics of collaborative facilitation and collaborative inhibition would affect teamwork within VEs. This study analyzed the impact of a virtual environment (VE) on the recall of individuals and members of nominal and collaborative groups. The research assessed costs and benefits for collaborative retrieval by testing the effect of experimental conditions, stimulus materials, group size, experimental conditions order, anxiety state, personality traits, gender group composition and social interactions. A total of 144 participants were engaged in a virtual Deese-Roediger-McDermott (DRM) classical paradigm, which involved remembering word lists across two successive sessions, in one of four protocols: I-individual/nominal, I I -nominal/individual, I I I -nominal/collaborative, I V -collaborative/nominal. Results suggested, in general, a reduced collaborative inhibition effect in the collaborative condition than the nominal and individual condition. A combined effect between experimental condition and difficulty of the task appears to explain the presence of collaborative inhibition or facilitation. Nominal groups appeared to enhance the collaborative groupsâ performance when virtual nominal groups come before collaborative groups. Variables such as personality traits, gender and social interactions may have a contribution to collaborative retrieval. In conclusion, this study indicated how VEs could maintain those peculiar social dynamics characterizing the participantsâ engagement in a task, both working together and individually, and could affect their intrinsic motivation as well as performances. These results could be exploited in order to design brand new and evidenced-based practices, to improve teleworking procedures and workers well-being, as well as teleworking teamwork effectiveness.</jats:p
Nuclear Track Detectors. Searches for Exotic Particles
We used Nuclear Track Detectors (NTD) CR39 and Makrofol for many purposes: i)
Exposures at the SPS and at lower energy accelerator heavy ion beams for
calibration purposes and for fragmentation studies. ii) Searches for GUT and
Intermediate Mass Magnetic Monopoles (IMM), nuclearites, Q-balls and
strangelets in the cosmic radiation. The MACRO experiment in the Gran Sasso
underground lab, with ~1000 m^2 of CR39 detectors (plus scintillators and
streamer tubes), established an upper limit for superheavy GUT poles at the
level of 1.4x10^-16 cm^-2 s^-1 sr^-1 for 4x10^-5 <beta<1. The SLIM experiment
at the high altitude Chacaltaya lab (5230 m a.s.l.), using 427 m^2 of CR39
detectors exposed for 4.22 y, gave an upper limit for IMMs of ~1.3x10^-15 cm^-2
s^-1 sr^-1. The experiments yielded interesting upper limits also on the fluxes
of the other mentioned exotic particles. iii) Environmental studies, radiation
monitoring, neutron dosimetry.Comment: Talk given at "New Trends In High-Energy Physics" (experiment,
phenomenology, theory) Yalta, Crimea, Ukraine, September 27-October 4, 200
Surface-acoustic-wave driven planar light-emitting device
Electroluminescence emission controlled by means of surface acoustic waves
(SAWs) in planar light-emitting diodes (pLEDs) is demonstrated. Interdigital
transducers for SAW generation were integrated onto pLEDs fabricated following
the scheme which we have recently developed. Current-voltage, light-voltage and
photoluminescence characteristics are presented at cryogenic temperatures. We
argue that this scheme represents a valuable building block for advanced
optoelectronic architectures
Triboelectric characterization of colloidal TiO2 for energy harvesting applications
Nowadays, energy-related issues are of paramount importance. Every energy transformation process results in the production of waste heat that can be harvested and reused, representing an ecological and economic opportunity. Waste heat to power (WHP) is the process of converting the waste heat into electricity. A novel approach is proposed based on the employment of liquid nano colloids. In this work, the triboelectric characterization of TiO2 nanoparticles dispersed in pure water and flowing in a fluorinated ethylene propylene (FEP) pipe was conducted. The idea is to exploit the waste heat to generate the motion of colloidal TiO2 through a FEP pipe. By placing an Al ring electrode in contact with the pipe, it was possible to accumulate electrostatic charges due to the triboelectric effect between the fluid and the inner pipe walls. A peristaltic pump was used to drive and control the flow in order to evaluate the performances in a broad fluid dynamic spectrum. The system generated as output relatively high voltages and low currents, resulting in extracted power ranging between 0.4 and 0.6 nW. By comparing the power of pressure loss due to friction with the extracted power, the electro-kinetic efficiency was estimated to be 20%
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