Evaluation of accelerometers to determine pavement deflections under traffic loads

The purpose of this work was to study the use of accelerometers to measure pavement deflections due to traffic loads. To this end, accelerometers were embedded in two sites: the full scale load simulator Circular Test Track (CTT) and the A1 motorway in Switzerland. Deflections were derived from acceleration measurements using an algorithm that double integrates the measured signal and corrects any errors derived from the procedure. In the motorway, deflections were monitored using a set of three magnetostrictive deflectometers. Additionally, the pavement's material viscoelastic parameters determined in the laboratory were incorporated in Finite Element (FE) models to estimate the theoretical deflections. The calculated deflections were then compared to the measured and to the theoretical deflections. Deflections calculated from acceleration showed a reasonable qualitative correlation to those measured by magnetostrictive deflectometers. In addition, the FE models revealed the inability of the accelerometers to measure very slow or quasi-static motio

Efficacy of screen recording in the other-revision of translations: episodic memory and event models

In a 2011 study, Angelone compared the self-revision results of graduate German translation students. Participants documented their original translations using Integrated Problem and Decision Reporting (IPDR) logs (Gile 2004), think-aloud protocols and screen recordings. They then used this documentation to assist self-revision of their translations. Angelone found a significant improvement in error detection overall and in each of six discrete error categories when participants used screen recordings to assist their self-revision. We sought to partially replicate Angelone’s findings concerning the efficacy of screen recording in translation revision. Instead of focusing on self-revision, we studied other-revision and broadened our scope to examine the behavior of graduate students in both Spanish and German translation. We hypothesized that error analysis overall would show that screen recording would again prove to be a more efficacious process protocol in support of revision than IPDR logs, as was the case in Angelone’s study. We also hypothesized that we would replicate his findings for each of the six error categories. The results partially confirmed Angelone’s results: screen recordings were significantly more efficacious than IPDR logs in overall error mitigation.En un estudio de 2011, Angelone comparó los resultados de auto-revisión de estudiantes graduados de traducción alemán-inglés. Los participantes documentaron sus traducciones originales mediante registros integrados de problemas y decisiones (IPDR, por sus siglas en inglés; Gile 2004), protocolos de pensamiento en voz alta, y grabaciones de pantalla. Después utilizaron esta documentación para facilitar la autorevisión de sus traducciones. Angelone encontró una mejora significativa general en la detección de errores y, en particular, en seis categorías específicas de errores cuando los participantes utilizaron las grabaciones de pantalla para sustentar su auto-revisión. En este estudio intentamos replicar parcialmente los resultados de Angelone con respecto a la eficacia de las grabaciones de pantalla para revisar traducciones. En lugar de centrarnos en la auto-revisión, estudiamos la revisión de traducciones ajenas. Según nuestra hipótesis de partida, el análisis de errores en general mostraría que las grabaciones de pantalla resultarían ser de nuevo un protocolo de proceso más eficaz en apoyo de la revisión que los registros IPDR, como en el estudio de Angelone. Otra hipótesis consistía en que replicaríamos sus resultados en cada una de las seis categorías de errores. Los resultados confirmaron parcialmente los obtenidos por Angelone: las grabaciones de pantalla fueron significativamente más eficaces que los registros IPDR en la mitigación general de errores

Neutron spectrometer for fast nuclear reactors

In this paper we describe the development and first tests of a neutron spectrometer designed for high flux environments, such as the ones found in fast nuclear reactors. The spectrometer is based on the conversion of neutrons impinging on $^6$Li into $\alpha$ and $t$ whose total energy comprises the initial neutron energy and the reaction $Q$-value. The $^6$LiF layer is sandwiched between two CVD diamond detectors, which measure the two reaction products in coincidence. The spectrometer was calibrated at two neutron energies in well known thermal and 3 MeV neutron fluxes. The measured neutron detection efficiency varies from 4.2$\times 10^{-4}$ to 3.5$\times 10^{-8}$ for thermal and 3 MeV neutrons, respectively. These values are in agreement with Geant4 simulations and close to simple estimates based on the knowledge of the $^6$Li(n,$\alpha$)$t$ cross section. The energy resolution of the spectrometer was found to be better than 100 keV when using 5 m cables between the detector and the preamplifiers.Comment: submitted to NI

Comparing the body mass variations in endemic insular species of the Genus Prolagus (Ochotonidae, Lagomorpha) in the pleistocene of Sardinia (Italy)

Prolagus figaro and P. sardus are part of an endemic insular anagenetic lineage that populated Sardinia since the earliest Late Pliocene to Holocene. BM of some populations of these two species was calculated using regression models. The best BM proxies for Prolagus are: femur length, zeugopod measurements and distal humerus diameter. The anagenetic lineage shows a BM increase of ca 20% from the populations of P. figaro (398-436 g) to P. sardus (504-525 g). The trend shown by the size of lower third premolar, even if not directly comparable with BM, is opposite (ca -30% at the transition P. figaro-P. sardus). Compared to P. cf. calpensis, a continental species of similar age, BM of P. figaro is ca +25%. The comparison with the insular endemic P. apricenicus evidenced differences in BM range and timespan required to attain it, due to the different size and palaeogeographical situation of the islands. Insular endemic Prolagus follow the small mammal pattern of Island Rule. Mein's (1983) biphasic model seems applicable to the evolution of P. figaro. A tachytelic phase followed by a bradytelic one seems to characterize also the appearance of P. sardus, at least for dental traits, a process probably triggered by important variations of abiotic and biotic traits of the environment, as indicated by the turnover that marks the onset of the Dragonara subcomplex. The prediction of life history traits and other biological attributes of Sardinian Prolagus using BM should be considered with caution due to the complexity of ecological selective regimes of Sardinia

Search for Neutron Flux Generation in a Plasma Discharge Electrolytic Cell

Following some recent unexpected hints of neutron production in setups like high-voltage atmospheric discharges and plasma discharges in electrolytic cells, we present a measurement of the neutron flux in a configuration similar to the latter. We use two different types of neutron detectors, poly-allyl-diglicol-carbonate (PADC, aka CR-39) tracers and Indium disks. At 95% C.L. we provide an upper limit of 1.5 neutrons cm^-2 s^-1 for the thermal neutron flux at ~5 cm from the center of the cell. Allowing for a higher energy neutron component the largest allowed flux is 64 neutrons cm^-2 s^-1. This upper limit is two orders of magnitude smaller than what previously claimed in an electrolytic cell plasma discharge experiment. Furthermore the behavior of the CR-39 is discussed to point our possible sources of spurious signals.Comment: 4 pages, 3 figure

Silicon Photo-Multiplier radiation hardness tests with a beam controlled neutron source

We report radiation hardness tests performed at the Frascati Neutron Generator on silicon Photo-Multipliers, semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated integrating up to 7x10^10 1-MeV-equivalent neutrons per cm^2. Detector performances have been recorded during the neutron irradiation and a gradual deterioration of their properties was found to happen already after an integrated fluence of the order of 10^8 1-MeV-equivalent neutrons per cm^2.Comment: 7 pages, 6 figures, Submitted to Nucl. Inst. Meth.

Trapping and detrapping effects in high-quality chemical-vapor-deposition diamond films: Pulse shape analysis of diamond particle detectors

An analysis of the time evolution of the response of diamond particle detectors is carried out, using as a probe 5.5 MeV α particles impinging on high-quality diamond films grown by microwave chemical vapor deposition (CVD). Both the amplitude and the time evolution of the pulses are shown to change drastically when the detector is preirradiated with β particles (pumping), a slow component developing after pumping, indicating carriers trapping and releasing (detrapping). Pulse shapes obtained for positive and negative detector polarities are compared in both the as-grown and pumped states. The presence of at least two trapping centers for holes is necessary to explain the results, the shallower having an activation energy of about 0.3 eV. The effects of pumping are clarified, and the different role played by electrons and holes is evidenced. We modify a previous model for trapping-detrapping behavior originally applied to Si(Li) detectors to describe the more complex behavior of CVD diamond detectors, and develop a computer simulation based on it. The simulated pulse shapes agree very well with experiment with reasonable values of the physical parameters involved, making this technique helpful for studying and identifying defects which are responsible for limitation of the efficiency of CVD diamond particle detectors. Field-assisted detrapping seems to take place for fields of about 104 V/cm

Experimental determination of electron and hole mean drift distance: Application to chemical vapor deposition diamond

A study was performed on the experimental determination of electron and hole mean drift distance in chemical vapor deposition polycrystalline diamond. Air was used as an absorbing layer in order to change the energy of the impinging α particles. The results showed that the pumping process was much more effective on hole conduction