Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and ...heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosmic-ray (CR) species at different modulation levels and at both polarities of the solar magnetic field. To do so in a self-consistent way, an iterative procedure was developed, where the GALPROP LIS output is fed into HelMod, providing modulated spectra for specific time periods of selected experiments to compare with the data; the HelMod parameter optimization is performed at this stage and looped back to adjust the LIS using the new GALPROP run. The parameters were tuned with the maximum likelihood procedure using an extensive data set of proton spectra from 1997 to 2015. The proposed LIS accommodate both the low-energy interstellar CR spectra measured by Voyager 1 and the high-energy observations by BESS, Pamela, AMS-01, and AMS-02 made from the balloons and near-Earth payloads; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The found solution is in a good agreement with proton, helium, and antiproton data by AMS-02, BESS, and PAMELA in the whole energy range.
Local interstellar spectra (LIS) of secondary cosmic-ray (CR) nuclei, lithium, beryllium, boron, and partially secondary nitrogen, are derived in the rigidity range from 10 MV to ∼200 TV using the ...most recent experimental results combined with state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. The lithium spectrum appears somewhat flatter at high energies compared to other secondary species, which may imply a primary lithium component. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. An iterative maximum-likelihood method is developed that uses GALPROP-predicted LIS as input to HelMod, which provides the modulated spectra for specific time periods of the selected experiments for the model-data comparison. The proposed LIS accommodates the low-energy interstellar spectra measured by Voyager 1, the High Energy Astrophysics Observatory-3 (HEAO-3), and the Cosmic Ray Isotope Spectrometer on board of the Advanced Composition Explorer (ACE/CRIS), as well as the high-energy observations by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), Alpha Magnetic Spectrometer-02 (AMS-02), and earlier experiments that are made deep in the heliosphere. The interstellar and heliospheric propagation parameters derived in this study are consistent with our earlier results for propagation of CR protons, helium, carbon, oxygen, antiprotons, and electrons.
The local interstellar spectrum (LIS) of cosmic-ray (CR) electrons for the energy range 1 MeV to 1 TeV is derived using the most recent experimental results combined with the state-of-the-art models ...for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. An iterative maximum-likelihood method is developed that uses GALPROP-predicted LIS as input to HelMod, which provides the modulated spectra for specific time periods of the selected experiments for model-data comparison. The optimized HelMod parameters are then used to adjust GALPROP parameters to predict a refined LIS with the procedure repeated subject to a convergence criterion. The parameter optimization uses an extensive data set of proton spectra from 1997 to 2015. The proposed CR electron LIS accommodates both the low-energy interstellar spectra measured by Voyager 1 as well as the high-energy observations by PAMELA and AMS-02 that are made deep in the heliosphere; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The interstellar and heliospheric propagation parameters derived in this study agree well with our earlier results for CR protons, helium nuclei, and anti-protons propagation and LIS obtained in the same framework.
Abstract
Composition and spectra of Galactic cosmic rays (CRs) are vital for studies of high-energy processes in a variety of environments and on different scales, for interpretation of
γ
-ray and ...microwave observations, for disentangling possible signatures of new phenomena, and for understanding of our local Galactic neighborhood. Since its launch, AMS-02 has delivered outstanding-quality measurements of the spectra of
,
, and nuclei:
1
H–
8
O,
10
Ne,
12
Mg,
14
Si. These measurements resulted in a number of breakthroughs; however, spectra of heavier nuclei and especially low-abundance nuclei are not expected until later in the mission. Meanwhile, a comparison of published AMS-02 results with earlier data from HEAO-3-C2 indicates that HEAO-3-C2 data may be affected by undocumented systematic errors. Utilizing such data to compensate for the lack of AMS-02 measurements could result in significant errors. In this paper we show that
a fraction
of HEAO-3-C2 data
match
available AMS-02 measurements quite well and can be used together with Voyager 1 and ACE-CRIS data to make
predictions
for the local interstellar spectra (LIS) of nuclei that are not yet released by AMS-02. We are also updating our already-published LIS to provide a complete set from
1
H–
28
Ni in the energy range from 1 MeV nucleon
−1
to ∼100–500 TeV nucleon
−1
, thus covering 8–9 orders of magnitude in energy. Our calculations employ the G
al
P
rop
–H
el
M
od
framework, which has proved to be a reliable tool in deriving the LIS of CR
,
e
−
, and nuclei
1
H–
8
O.
Local interstellar spectra (LIS) of primary cosmic ray (CR) nuclei, such as helium, oxygen, and mostly primary carbon are derived for the rigidity range from 10 MV to ∼200 TV using the most recent ...experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HelMod, are combined into a single framework that is used to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. The developed iterative maximum-likelihood method uses GALPROP-predicted LIS as input to HelMod, which provides the modulated spectra for specific time periods of the selected experiments for model-data comparison. The interstellar and heliospheric propagation parameters derived in this study are consistent with our prior analyses using the same methodology for propagation of CR protons, helium, antiprotons, and electrons. The resulting LIS accommodate a variety of measurements made in the local interstellar space (Voyager 1) and deep inside the heliosphere at low (ACE/CRIS, HEAO-3) and high energies (PAMELA, AMS-02).
Massification of Electric vehicles (EVs) is becoming a worldwide reality as a means to combat climate change and local pollution. Considering that most of the time vehicles are in parking places, ...there is an opportunity for using EVs to provide some valuable services to the power network. In particular, EVs can provide ancillary services in electricity markets through an aggregating agent. To this end, EVs aggregators need to develop decision support tools to optimally allocate energy and regulation resources considering power network constraints. Unlike optimization models for EVs aggregators currently available in the literature, in this paper we propose an optimization approach for EVs aggregators that jointly considers the most important aspects influencing EVs profitability, such as uncertainty, drivers’ patterns, capacity constraints, state of charge constraints, regulation demand constraints, regulation offer constraints, regulation bounds constraints, and power-system security constraints. The optimization problem is formulated as a mixed-integer linear programming problem, thus ensuring global optimality. Results are presented in the form of the hourly allocation for charging/discharging power profiles, distinguishing between day-ahead energy and capacity/energy for regulation, and the profit that can be reached, while accounting for network constraints.
The proposed model is illustrated through a case study, which allows us to show that EVs aggregators allow for leading to a more reliable power system operation, avoiding transmission lines congestion, while providing important profits for EV owners who are able to provide regulation services.
•EV aggregators allow for a more reliable power system operation.•EV owners can attain profits from participating in energy markets.•An EV model featuring uncertainty, driving patterns, state of charge and capacity.•A relatively simple one-stage mixed-integer linear programming optimization model.
We explore the accuracy of the clustering-based redshift estimation proposed by Ménard et al. when applied to VIMOS Public Extragalactic Redshift Survey (VIPERS) and Canada–France–Hawaii Telescope ...Legacy Survey (CFHTLS) real data. This method enables us to reconstruct redshift distributions from measurement of the angular clustering of objects using a set of secure spectroscopic redshifts. We use state-of-the-art spectroscopic measurements with i
AB < 22.5 from the VIPERS as reference population to infer the redshift distribution of galaxies from the CFHTLS T0007 release. VIPERS provides a nearly representative sample to a flux limit of i
AB < 22.5 at a redshift of >0.5 which allows us to test the accuracy of the clustering-based redshift distributions. We show that this method enables us to reproduce the true mean colour–redshift relation when both populations have the same magnitude limit. We also show that this technique allows the inference of redshift distributions for a population fainter than the reference and we give an estimate of the colour–redshift mapping in this case. This last point is of great interest for future large-redshift surveys which require a complete faint spectroscopic sample.
During seed germination, iron (Fe) stored in vacuoles is exported by the redundant NRAMP3 and NRAMP4 transporter proteins. A double nramp3 nramp4 mutant is unable to mobilize Fe stores and does not ...develop in the absence of external Fe. We used RNA sequencing to compare gene expression in nramp3 nramp4 and wild type during germination and early seedling development. Even though sufficient Fe was supplied, the Fe-responsive transcription factors bHLH38, 39, 100, and 101 and their downstream targets FRO2 and IRT1 mediating Fe uptake were strongly upregulated in the nramp3 nramp4 mutant. Activation of the Fe deficiency response was confirmed by increased ferric chelate reductase activity in the mutant. At early stages, genes important for chloroplast redox control (FSD1 and SAPX), Fe homeostasis (FER1 and SUFB), and chlorophyll metabolism (HEMA1 and NYC1) were downregulated, indicating limited Fe availability in plastids. In contrast, expression of FRO3, encoding a ferric reductase involved in Fe import into the mitochondria, was maintained, and Fe-dependent enzymes in the mitochondria were unaffected in nramp3 nramp4. Together, these data show that a failure to mobilize Fe stores during germination triggered Fe deficiency responses and strongly affected plastids, but not mitochondria.
•Universal calibrations for microplate assays.•Simplified pathlength corrections for microplate FRAP assays.•Microplate FRAP assay for total antioxidant capacity.•Manuka honey FRAP value.•Manuka UMF ...rating predicts total phenols content.
The ferric reducing antioxidant power (FRAP) assay was recently adapted to a microplate format. However, microplate-based FRAP (mFRAP) assays are affected by sample volume and composition. This work describes a calibration process for mFRAP assays which yields data free of volume effects. From the results, the molar absorptivity (ε) for the mFRAP assay was 141,698M−1cm−1 for gallic acid, 49,328M−1cm−1 for ascorbic acid, and 21,606M−1cm−1 for ammonium ferrous sulphate. The significance of ε (M−1cm−1) is discussed in relation to mFRAP assay sensitivity, minimum detectable concentration, and the dimensionless FRAP-value. Gallic acid showed 6.6mol of Fe2+ equivalents compared to 2.3mol of Fe+2 equivalents for ascorbic acid. Application of the mFRAP assay to Manuka honey samples (rated 5+, 10+, 15+, and 18+ Unique Manuka Factor; UMF) showed that FRAP values (0.54–0.76mmol Fe2+ per 100g honey) were strongly correlated with UMF ratings (R2=0.977) and total phenols content (R2=0.982)whilst the UMF rating was correlated with the total phenols (R2=0.999). In conclusion, mFRAP assay results were successfully standardised to yield data corresponding to 1-cm spectrophotometer which is useful for quality assurance purposes. The antioxidant capacity of Manuka honey was found to be directly related to the UMF rating.
The possibility of a relevant contribution of biomass burning for domestic heating to PM10 in the urban area of Rome was explored. The concentration of levoglucosan was determined for 31 months in ...Rome and in a nearby peri-urban area. During the cold season it reached several hundreds of ng/m3 at both sites, with a clear inverse relationship with air temperature. During the summer it remained well below 100 ng/m3. Although at the peri-urban station the concentration was about 50% higher than at the urban site, the two seasonal patterns show a very good agreement (R2 = 0.95), pointing at a main contribution of biomass burning in both areas.
Additional information came from the comparison of the 2-h time pattern of levoglucosan and the mixing conditions of the atmosphere, evaluated by monitoring natural radioactivity. During the summer levoglucosan concentration followed the pattern of natural radioactivity, indicating a contribution from many small sources scattered on a wide area (wildfires, barbecues, agricultural fires). During the heating season the activity of a source that switched in the early afternoon and switched off before midnight was highlighted. A 2-h delay between levoglucosan time patterns at the peri-urban and the urban site suggests that biomass burning mainly occurs outside Rome and the combustion products are then transported towards the city centre.
Biomass burning contribution to PM10 was estimated as 12% at the peri-urban site and 6.7% inside the city, with relevant implications for the health of the about 2.800.000 citizens living in the urban area of Rome.
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•During the winter we measured high levoglucosan concentrations in the area of Rome.•The concentration increased in the early afternoon and decreased after midnight.•In the peri-urban area we measured higher values and a 2-h shift with respect to Rome.•A substantial transport from the peri-urban area to the city centre was recognized.•The average contribution of biomass burning to PM10 in the urban area was 6.7%.
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