Search results for "flux"
showing 10 items of 1392 documents
Non-stationary nature of SO2 degassing at Etna’s North-east crater (Italy).
2012
Investigating Etna’s long-term SO2 flux behaviour has led to important conclusions on the structure of the volcano’s magma feeding system, magma production (and degassing) rates, and causes for the excess degassing behaviour. Nonetheless, our knowledge of the short-term (timescales of seconds to a few hours) behaviour of magmatic volatiles (e.g., bubble coalescence, separate ascent and surface bursting of gas-rich bubbles) in the volcano’s upper feeding conduit system is still fragmentary, and based on indirect evidences (petrologic-textural data, observation of geophysical signals , physical modelling and laboratory experiments). In the past, direct gas flux measurements at Etna have been ta…
Calculation of total muon flux observed by Muon Monitor experiment
2017
An approach to calculate the flux of cosmicgenic muons detected by Muon Monitor experiment in lab LAB2400 of the Underground Laboratory in Canfranc (LSC) is described. The measuring apparatus consists of three layers of SC16 scintillation matrix detectors. The hardware function of the detector assembly was determined using computer simulation. Obtained value of the total muon ux turned out to be equal to (4.35 ± 0.2) × 10−3 m −2 s −1. peerReviewed
Controllable morphology of flux avalanches in microstructured superconductors
2014
The morphology of abrupt bursts of magnetic flux into superconducting films with engineered periodic pinning centers (antidots) has been investigated. Guided flux avalanches of thermomagnetic origin develop a tree-like structure, with the main trunk perpendicular to the borders of the sample, while secondary branches follow well-defi ned directions determined by the geometrical details of the underlying periodic pinning landscape. Strikingly, we demonstrate that in a superconductor with relatively weak random pinning, the morphology of such flux avalanches can be fully controlled by proper combinations of lattice symmetry and antidot geometry. Moreover, the resulting flux patterns can be re…
Technical and economical comparison between NdFeB and hard ferrites linear electrical generators from sea waves
2015
In this paper the authors perform a technical-economic comparison of two different Tubular Permanent Magnet Linear Machines for sea waves generation by using finite elements analysis. The first configuration includes ferrite rings while the second configuration includes neodymium-iron-boron rings. In order to compare the two types in economic and technical terms, a detailed analysis of the main figures of merit of the two configurations has been carried out. In particular, significant data such as flux distribution, rated voltage and current, axial force, electric power, realization cost and maintenance cost have been compared.
Search for a diffuse flux of high-energy ¿µ with the ANTARES neutrino telescope
2011
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A $(0.83\times 2\pi)$ sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an $E^{-2}$ flux spectrum, a 90% c.l. upper limit on the diffuse $\nu_\mu$ flux of $E^2\Phi_{90%} = 5.3 \times 10^{-8} \ \mathrm{GeV\ cm^{-2}\ s^{-1}\ sr^{-1}} $ in the energy range 20 TeV - 2.5 PeV is obtained. Other signal models with differ…
Solar radiative effects of a Saharan dust plume observed during SAMUM assuming spheroidal model particles
2011
The solar optical properties of Saharan mineral dust observed during the Saharan Mineral Dust Experiment (SAMUM) were explored based on measured size-number distributions and chemical composition. The size-resolved complex refractive index of the dust was derived with real parts of 1.51–1.55 and imaginary parts of 0.0008–0.006 at 550 nm wavelength. At this spectral range a single scattering albedo ω o and an asymmetry parameter g of about 0.8 were derived. These values were largely determined by the presence of coarse particles. Backscatter coefficients and lidar ratios calculated with Mie theory (spherical particles) were not found to be in agreement with independently measured lidar data.…
Nordic Higher Education in Flux: System Evolution and Reform Trajectories
2019
AbstractThis chapter provides a brief description of how the four national systems included in this study—Denmark, Finland, Norway, and Sweden—are currently organised and structured. In doing so, it illuminates several specific features such as the types and sizes of the institutions, enrolment patterns, performance measures, and funding. In addition, the chapter gives a snapshot of how higher education systems have evolved historically by shedding light on policy dynamics from the late 1990s to 2013, the baseline period for the FINNUT comparative study, the research project that provides the basis for this edited volume. This is followed by a section describing the aim, methods, theoretica…
¿Me voy o me quedo? Factores que influyen en la decisión de abandonar el lugar de nacimiento.
2014
Múltiples factores influyen en la decisión de dispersarse y en cuándo iniciar la dispersión, y su estudio proporciona evidencias de las causas y los determinantes de la dispersión. Los animales abandonan el lugar de nacimiento para dar solución a tres problemas fundamentales: pérdida de calidad del hábitat, competencia por los recursos, y riesgo de consanguinidad. La dispersión, sin embargo, no se lleva a cabo hasta que los individuos alcanzan una condición física adecuada, que permita alcanzar con éxito un nuevo lugar de asentamiento.
High Bias Voltage CZT Detectors for High-flux Measurements
2017
In this work, we present the performance of new travelling heater method (THM) grown CZT detectors, recently developed at IMEM-CNR Parma, Italy. Thick planar detectors (3 mm thick) with gold electroless contacts on CZT crystals grown by Redlen Technologies (Victoria BC, Canada) were realized, with a planar cathode covering the detector surface (4.1 x 4.1 mm(2)) and a central anode (2 x 2 mm(2)) surrounded by a guard ring electrode. The detectors, characterized by low leakage currents at room temperature (4.7 nA/cm(2) at 1000 V/cm), allow good room temperature operation even at high bias voltages (> 7000 V/cm). At low rates, the detectors exhibit an energy resolution around 4 % FWIEM at 59.5…
Microscale X-ray mapping of CZT arrays: Spatial dependence of amplitude, shape and multiplicity of detector pulses
2018
In this work, we present the results of a microscale X-ray mapping of a 2 mm thick CZT pixel detector, with pixel pitches of 500 μm and 250 μm, using collimated synchrotron X-ray sources at the Diamond Light source (U. K.). The detector is dc coupled to a fast and low noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to perform online fast pulse shape and height analysis (PSHA), with low dead time and reasonable energy resolution at both low and high fluxes. The detector allows high bias voltage operation (> 5000 V/cm) and good energy resolution at room temperature (5.3 %, 2.3 % and 2.1 % FWHM at 22.1, 59…