741 research outputs found
EVALUATION OF ENVIRONMENTAL NEUTRON DOSE AT GROUND LEVEL
This work presents the results of two cycles of neutron dose rate measurements realized using an ALNOR
2202D Neutron Dose Rate Meter whose time response is acquired and analyzed through a controlled ORTEC MCS-32 acquisition card in Windows environment. The data obtained have been compared with values from previous
experimental surveys and with the data provided by the worldwide main observatories. It has been also verified the
influence of the fluctuations in the flux of cosmic rays during the course of a solar cycle. By comparing the realized
measurements and the data provided by the cosmic ray monitoring networks it is also possible to obtain a value of
ambient dose equivalent rate and neutron flux rate which can be used as a reference for design a neutron irradiation
testing of electronic devices
Proximity effect in planar superconducting tunnel junctions containing Nb/NiCu superconductor/ferromagnet bilayers
We present experimental results concerning both the fabrication and characterization of superconducting tunnel junctions containing superconductor/ferromagnet (S/F) bilayers made by niobium (S) and a weak ferromagnetic Ni0.50Cu0.50 alloy. Josephson junctions have been characterized down to T=1.4 K in terms of current-voltage I-V characteristics and Josephson critical current versus magnetic field. By means of a numerical deconvolution of the I-V data the electronic density of states on both sides of the S/F bilayer has been evaluated at low temperatures. Results have been compared with theoretical predictions from a proximity model for S/F bilayers in the dirty limit in the framework of Usadel equations for the S and F layers, respectively. The main physical parameters characterizing the proximity effect in the Nb/NiCu bilayer, such as the coherence length and the exchange field energy of the F metal, and the S/F interface parameters have been also estimated
L’identità come bene culturale tra sfruttamento e appartenenza Tracce, segni e localizzazione del cibo popolare a Napoli
Food as a cultural asset contributes to the construction of local identity. The paper analyzes the contrast between glo- balization and the opposite trend. The first tends to homolo- gation recognizing something as typical always re-proposed it in the same way to mass tourism, while the other trend seeks an exaltation and enhancement of the authenticity of popular food cultures linked to the local dimension which, by their nature, are in constant transformation. The reflection fo- cuses on the city of Naples, emphasizing the role of popular food culture in the construction of a common imaginary of the city, and reporting the analysis carried out on some typo- logical invariants recognized in the communication systems of food shops and restaurants
Assessment of contamination of Salmonella spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irradiation
This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepper and sesame
Use of Sawing Waste from Zeolitic Tuffs in the Manufacture of Ceramics
This paper investigates the thermal transformation of powders of volcanic tuffs that are used as building stones and aims at thermally transforming them into ceramics. The following positive indications concerning this thermal transformation were found: (1) the structural evolution which brings products similar to traditional ceramics, (2) the good ability to give rise to dense and compact final products, and (3) the good mechanical properties and the lovely appearance of the final products. Nevertheless, the high values of linear shrinkages recorded in this work seem to strongly hinder the thermal transformation of this powder-like waste into ceramics. However, mixing this by-product with other powder-like waste exhibiting higher-dimensional stability, such as those deriving from sawing of granites, appears proper
Supporting University Students During the Pandemic: A Study on The Efficacy of a Mentalizing Online Group Counselling
Background: University counselling services assume a fundamental support function for students who are facing moments of crisis during their academic career. Such services often aim to reduce drop-out rates and achieve improvement in terms of psychological well-being. COVID-19 contagion containment measures have also had an impact on the psychological health of university students and their ability to cope with important developmental tasks. It has become necessary, therefore, to offer online counselling services which has become, however, the means of choice to support students during the university course in the pandemic era, as a complementary intervention to the traditional face-to-face approach.
Methods: In a clinical and health psychology perspective, this study aims to analyze the efficacy of 13 online counselling groups involving 66 underachieving students, lagging with their studies. The intervention has adopted the methodology of the Narrative Mediation Path, which aims at promoting mentalization, academic engagement and psychological well-being in order to have an impact on students’ academic performance and prevent university dropouts. At the beginning and end of counselling the following measures were administered: a) Reflective Functioning Questionnaire, b) Psychological General Well-Being Index Short Form, c) Academic Performance Inventory, d) University Student Engagement Inventory, e) Group Climate Questionnaire.
Results: The results showed that online counselling groups enabled an overall improvement in all the variables considered.
Conclusion: Overall, the present study showed the efficacy of the online group counselling service in supporting students during the pandemic period and in coping with the difficulties encountered during the academic career
Characterization of quasiparticle relaxation times in microstrips of NbReN for perspective applications for superconducting single-photon detectors
The study of the flux-flow instability in superconducting materials has recently gained renewed attention due to
its potential implications for the use of the analyzed materials as micrometer-sized superconducting detectors
for single photons. The values of the quasiparticle relaxation time (Ï„E) measured for these detectors are affected
by pinning properties. Here, we report electric transport properties of NbReN microstrips of different quality.
For the strip characterized by high resistivity, and large critical currents and pinning, we estimate a value of
Ï„E that is almost two orders of magnitude larger compared to that of another strip with a smaller value for
the critical current, for which we measure τE ∼ 12 ps. This low value is comparable to those reported in the
literature for microstrips made of other highly-disordered superconductors. Our results suggest that NbReN
microstrips have great potential for the realization of superconducting single-photon detectors, depending on
further optimization of their fabrication process and the superconducting properties affected by it
Zeolite-feldspar epiclastic rocks as flux in ceramic tile manufacturing
Low-cost, naturally-occurring mixtures of feldspar and zeolite occurring in epiclastic rocks are promising substitutes for conventional quartz-feldspathic fluxes in ceramic bodies, since their fusibility and low hardness are expected to improve both grinding and sintering. Three epiclastic outcrops, with a different zeolite-to-feldspar ratio, were characterized (XRPD, fusibility) and tested in porcelain stoneware bodies; their behaviour during processing was appraised and compared with that of a reference. The addition of an epiclastic rock (20 wt.%), replacing rhyolite and aplite fluxes, brought about some significant advantages, mainly represented by better grindability, lower firing temperature with improved mechanical strength and lower porosity. Disadvantages concern increased slip viscosity, worse powder compressibility, resulting in larger firing shrinkage, and a darker colour of the tiles due to relatively high amounts of iron oxide
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