Search results for "emission"
showing 10 items of 2441 documents
First evidence of multiple β-delayed neutron emission for isotopes with a > 100
2017
The β-delayed neutron emission probability, Pn, of very neutron-rich nuclei allows us to achieve a better understanding of the nuclear structure above the neutron separation energy, Sn. The emission of neutrons can become the dominant decay process in neutron-rich astrophysical phenomena such as the rapid neutron capture process (r-process). There are around 600 accessible isotopes for which β-delayed one-neutron emission (β1n) is energetically allowed, but the branching ratio has only been determined for about one third of them. β1n decays have been experimentally measured up to the mass A ∼ 150, plus a single measurement of 210Tl. Concerning two-neutron emitters (β2n), ∼ 300 isotopes are …
Can differences in microbial abundances help explain enhanced N2O emissions in a permanent grassland under elevated atmospheric CO2?
2011
LONG-TERM EFFECT OF TILLAGE AND CROP SEQUENCE ON SOIL MICROBIAL COMMUNITY AND NITROGEN EMISSIONS IN MEDITERRANEAN ENVIRONMENT
The interactive effects of various nitrogen fertiliser formulations applied to urine patches on nitrous oxide emissions in grassland
2017
AbstractPasture-based livestock agriculture is a major source of greenhouse gas (GHG) nitrous oxide (N2O). Although a body of research is available on the effect of urine patch N or fertiliser N on N2O emissions, limited data is available on the effect of fertiliser N applied to patches of urinary N, which can cover up to a fifth of the yearly grazed area. This study investigated whether the sum of N2O emissions from urine and a range of N fertilisers, calcium ammonium nitrate (CAN) or urea ± urease inhibitor ± nitrification inhibitor, applied alone (disaggregated and re-aggregated) approximated the N2O emission of urine and fertiliser N applied together (aggregated). Application of fertili…
Inference of proto-neutron star properties from gravitational-wave data in core-collapse supernovae
2021
The eventual detection of gravitational waves from core-collapse supernovae (CCSN) will help improve our current understanding of the explosion mechanism of massive stars. The stochastic nature of the late post-bounce gravitational wave signal due to the non-linear dynamics of the matter involved and the large number of degrees of freedom of the phenomenon make the source parameter inference problem very challenging. In this paper we take a step towards that goal and present a parameter estimation approach which is based on the gravitational waves associated with oscillations of proto-neutron stars (PNS). Numerical simulations of CCSN have shown that buoyancy-driven g-modes are responsible …
Gaia-ESO Survey: H{alpha} emission stars catalogue
2015
We discuss the properties of H{alpha} emission stars across the sample of 22035 spectra from the Gaia-ESO Survey internal data release, observed with the GIRAFFE instrument and largely belonging to stars in young open clusters. Automated fits using two independent Gaussian profiles and a third component accounting for the nebular emission allow us to discern distinct morphological types of H{alpha} line profiles with the introduction of a simplified classification scheme. Altogether we find 3765 stars with intrinsic emission and sort their spectra into eight distinct morphological categories: single component emission, emission blend, sharp emission peaks, double emission, P-Cygni, inverted…
STRATEGIES FOR A MORE SUSTAINABLE HOME FOOD DELIVERY SYSTEM: THE CASE STUDY OF DELIVEROO
2020
The aim of this work is to investigate the main enabling factors facilitating the diffusion of the emobility in the food delivery sector through the analysis of the Deliveroo case study. Deliveroo s.r.l. has been chosen for two main reasons. First, the growing importance of the company in the food delivery market, with an annual turnover increase of +120 million euros in 2017, becoming one of the major national players for food delivery. Second, the company recently adopted a strategy to support the diffusion of electric mobility for home delivery through the subscription of specific agreements.
Pulsating B and Be stars in the Small Magellanic Cloud
2008
Context: Stellar pulsations in main-sequence B-type stars are driven by the kappa-mechanism due to the Fe-group opacity bump. The current models do not predict the presence of instability strips in the B spectral domain at very low metallicities. As the metallicity of the SMC is lower than Z=0.005, it constitutes a very suitable object to test these predictions. Aims: The main objective is to investigate the existence of B-type pulsators at low metallicities, searching for short-term periodic variability in absorption-line B and Be stars in the SMC. The analysis has been performed in a sample of 313 B and Be stars with fundamental astrophysical parameters accurately determined from high-res…
Aircraft measurements of aerosol particles and trace gases over the Southern Baltic Sea during the BALTIC'15 campaign in 2015
2019
During the BALTIC'15 campaign, conducted in August 2015 over the Southern Baltic Sea, trace gasses (CO2/O3/NOy/SO2) and aerosol particles (number concentration of total/non-volatile/Aitken mode/ Accumulation mode/Coarse mode/refractory black carbon, aerosol extinction coefficient, mass concentration of refractory black carbon were measured). Observations were performed on board of the Alfred Wegener Institute research aircraft Polar 5 during 4 flights: - Scientific flight 1 (SF1) 26 August 2015 - Scientific flight 2 (SF2) 28 August 2015 - Scientific flight 3 (SF3) 28 August 2015 - Scientific flight 4 (SF4) 30 August 2015
Transition-edge sensors for particle-induced X-ray emission spectrometry
2018
A transition-edge sensor array has been applied to particle-induced X-ray emission. We have characterized the detector for quantitative analysis and obtained minimum detection limit over two orders of magnitude better compared to a silicon drift detector. We have also studied chemical effects in analysis of Ti, TiO2 and TiN using proton and heavy ion beams. A chemical shift for TiO2 was observed in proton measurements, and relative multiple ionization X-ray satellite line intensities changed between metallic Ti and other compounds with heavy ions. Detection of low energy X-rays down to 0.5 keV was achieved by installing a polycapillary lens in front of the transition-edge sensor array in ex…