877 research outputs found
Determining F-factor using ground-based Doppler radar: Validation and results
Using a two-dimensional linear least-squares method applied to Doppler radar data, we test the viability of determining F-factor remotely. The ultimate application of such an algorithm will be supplying real-time F-factor maps, derived from ground-based Doppler radars to air traffic control personnel and pilots. Data from NASA deployments to the MIT/Lincoln Lab TDWR testbed radar in Orlando in 1991 and 1992 along with NASA deployments to the NCAR TDWR testbed radar in Denver are examined. Preliminary analyses show that the two-dimensional method correlates reasonably well with in situ measurements. Several effects, independent of the method used, act to reduce the correlation to less than one. These include time differences between radar and aircraft data, vertical misalignment between the aircraft and the radar beam, different spatial resolution scales between aircraft and radar data, inhomogeneous radar beam filling, noise in radar data that eludes filtering, and phase lag between time and space due to low pass filtering of the aircraft data. In the final assessment, it appears that a shear-based F-factor algorithm is preferable to the currently implemented TDWR algorithms which lack any local shear estimates
Toroidal magnetized iron neutrino detector for a neutrino factory
A neutrino factory has unparalleled physics reach for the discovery and measurement of CP violation in the neutrino sector. A far detector for a neutrino factory must have good charge identification with excellent background rejection and a large mass. An elegant solution is to construct a magnetized iron neutrino detector (MIND) along the lines of MINOS, where iron plates provide a toroidal magnetic field and scintillator planes provide 3D space points. In this paper, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of large θ13. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent δCP reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of δCP
Temperature Increase Dependence on Ultrasound Attenuation Coefficient in Innovative Tissue-mimicking Materials
Although high intensity focused ultrasound beams (HIFU) have found rapid agreement in clinical environment as a tool for non
invasive surgical ablation and controlled destruction of cancer cells, some aspects related to the interaction of ultrasonic waves
with tissues, such as the conversion of acoustic energy into heat, are not thoroughly understood. In this work, innovative tissue-
mimicking materials (TMMs), based on Agar and zinc acetate, have been used to conduct investigations in order to determine a
relation between the sample attenuation coefficient and its temperature increase measured in the focus region when exposed to an
HIFU beam. An empirical relation has been deduced establishing useful basis for further processes of validations of numerical
models to be adopted for customizing therapeutic treatments
The Golden Channel at a Neutrino Factory revisited: improved sensitivities from a Magnetised Iron Neutrino Detector
This paper describes the performance and sensitivity to neutrino mixing
parameters of a Magnetised Iron Neutrino Detector (MIND) at a Neutrino Factory
with a neutrino beam created from the decay of 10 GeV muons. Specifically, it
is concerned with the ability of such a detector to detect muons of the
opposite sign to those stored (wrong-sign muons) while suppressing
contamination of the signal from the interactions of other neutrino species in
the beam. A new more realistic simulation and analysis, which improves the
efficiency of this detector at low energies, has been developed using the GENIE
neutrino event generator and the GEANT4 simulation toolkit. Low energy neutrino
events down to 1 GeV were selected, while reducing backgrounds to the
level. Signal efficiency plateaus of ~60% for and ~70% for
events were achieved starting at ~5 GeV. Contamination from the
oscillation channel was studied for the first
time and was found to be at the level between 1% and 4%. Full response matrices
are supplied for all the signal and background channels from 1 GeV to 10 GeV.
The sensitivity of an experiment involving a MIND detector of 100 ktonnes at
2000 km from the Neutrino Factory is calculated for the case of . For this value of , the accuracy in the
measurement of the CP violating phase is estimated to be , depending on the value of ,
the CP coverage at is 85% and the mass hierarchy would be determined
with better than level for all values of
Improving the light collection efficiency of silicon photomultipliers through the use of metalenses
Metalenses are optical devices that implement nanostructures as phase shifters to focus incident light. Their compactness and simple fabrication make them a potential cost-effective solution for increasing light collection efficiency in particle detectors with limited photosensitive area coverage. Here we report on the characterization and performance of metalenses in increasing the light collection efficiency of silicon photomultipliers (SiPM) of various sizes using an LED of 630 nm, and find a six to seven-fold increase in signal for a 1.3×1.3 mm² SiPM when coupled with a 10-mm-diameter metalens manufactured using deep ultraviolet stepper lithography. Such improvements could be valuable for future generations of particle detectors, particularly those employed in rare-event searches such as dark matter and neutrinoless double beta decay
Influence of temperature, pressure and water vapour on CO2 separation
2020.01555.CEECIND )
© 2023The effect of temperature, pressure, and humidity content in the gas separation performance of iongel membranes are crucial parameters that should be assessed to determine the real potential of these materials to be used in CO2 separation processes. In this work, we present a detailed study on the impact of temperature (303, 323 and 353 K), pressure (2 and 4 bar), gas composition and water vapour content (between 11 and 21% of relative humidity) on the performance of iongels containing azo-porous organic polymers (azo-POPs), for CO2/N2 and CO2/CH4 binary gas separations. The iongels combining 80 wt% of the ionic liquid (IL) [C2mim][TFSI], 20 wt% of poly(ethylene glycol) diacrylate (PEGDA) and 0.5 wt% of different azo-POPs were prepared by a solvent-free UV curing method. At the lower temperature, the pressure increase seems to have a negative impact on the CO2 permeability of the prepared mixed matrix iongel membranes (MMIMs). However, the opposite behaviour was found when the temperature increases. Moreover, the presence of humidity in the feed gas stream affects the gas separation performance of the studied iongels, since the CO2 permeability greatly increases with increasing humidity in the gas mixture, while the selectivity decreases, for both gas separations under study. In general, the high pressure and temperature, and the presence of humidity have a significant influence on the separation performance of the studied iongel membranes, due to induced alterations in their structure and overall stability.publishersversionpublishe
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