XIPE: the X-ray imaging polarimetry explorer

Abstract X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 % in the 2-10 keV band in 105 s for pointed observations, and 0.6 % for an X10 class solar flare in the 15-35 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14.7 arcmin × 14.7 arcmin. The spectral resolution is 20 % at 6 keV and the time resolution is 8 mus. The imaging capabilities of the JET-X optics and of the GPD have been demonstrated by a recent calibration campaign at PANTER X-ray test facility of the Max-Planck-Institut für extraterrestrische Physik (MPE, Germany). XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil). The data policy is organized with a Core Program that comprises three months of Science Verification Phase and 25 % of net observing time in the following 2 years. A competitive Guest Observer program covers the remaining 75 % of the net observing time

Limiti e potenzialità della filiera latte africana in area subsahariana : l'esempio di un progetto pilota

The urban and periurban milk chain at Maroua (Cameroun) - In the last years the urbanization and the population growth led to a change in food needs of big cities in the Sahel area, where milk and milk products are considered more and more as an essential element in human nutrition. The aim of this study was to obtain information about the urban and periurban milk chain at Maroua (Cameroun). The survey was based on a questionnaire on sites, transformation methods and relationship among actors involved in the milk chain. The questionnaire was structured in open-ended questions to analyse each step of the milk chain: production, processing, collection, sale and consumption. The study underlined the coexistence of two milk chains: the urban and the periurban one. In the first one, farmers and consumers are close: the delivery time is short and the sale of fresh milk is possible. On the contrary, the long delivery time needed to bring milk to the urban markets from the periurban area forces those farmers to use milk for the production of yogurt and curdled milk, as cheese is not common in this area. In both the urban and periurban chains, a part of the milk is sold to hotels, restaurants and stores of Maroua. The study pointed out a loss of organization among the different steps of the milk chain, mainly due to the lack of consorting (cooperatives, associations, etc.). The feebleness in structuring decreases the power in negotiation of the actors of the milk chain, producing an outflow of demand on the market

Particle emission from heavy-duty engine fuelled with blended diesel and biodiesel

In this study, particulate matter (PM) were characterized from a place impacted by heavy-duty vehicles (Bus Station) fuelled with diesel/biodiesel fuel blend (B3) in the city of Londrina, Brazil. Sixteen priority polycyclic aromatic hydrocarbons (PAH) concentrations were analyzed in the samples by their association with atmospheric PM, mass size distributions and major ions (fluorite, chloride, bromide, nitrate, phosphate, sulfate, nitrite, oxalate; fumarate, formate, succinate and acetate; lithium, sodium, potassium, magnesium, calcium and ammonium). Results indicate that major ions represented 21.2% particulate matter mass. Nitrate, sulfate, and ammonium, respectively, presented the highest concentration levels, indicating that biodiesel may also be a significant source for these ions, especially nitrate. Dibenzo[a,h]anthracene and indeno[1,2,3,-cd]pyrene were the main PAH found, and a higher fraction of PAH particles was found in diameters lower than 0.25 mu m in Londrina bus station. The fine and ultrafine particles were dominant among the PM evaluated, suggesting that biodiesel decreases the total PAH emission. However, it does also increase the fraction of fine and ultrafine particles when compared to diesel.National Institute of Science and Technology for Energy and Environment (INCTEA)National Institute of Science and Technology for Energy and Environment (INCT-EA) [15/2008

Effectiveness and tolerability of perampanel in children and adolescents with refractory epilepsies-An Italian observational multicenter study.Effectiveness and tolerability of perampanel in children and adolescents with refractory epilepsies-An Italian observational multicenter study

31nononePurpose To evaluate the efficacy and tolerability of Perampanel (PER) in children and adolescents with refractory epilepsies in daily clinical practice conditions. Patients and methods This Italian multicenter retrospective observational study was performed in 16 paediatric epilepsy centres. Inclusion criteria were: (i) ≤18 years of age, (ii) history of refractory epilepsy, (iii) a follow-up ≥5 months of PER add-on therapy. Exclusion criteria were: (i) a diagnosis of primary idiopathic generalized epilepsy, (ii) variation of concomitant AEDs during the previous 4 weeks. Response was defined as a ≥50% reduction in monthly seizure frequency compared with the baseline. Results 62 patients suffering from various refractory epilepsies were included in this study: 53% were males, the mean age was 14.2 years (range 6–18 years), 8 patients aged <12 years. Mean age at epilepsy onset was 3.4 years and the mean duration of epilepsy was 10.8 years (range 1–16), which ranged from 2 seizures per-month up to several seizures per-day (mean number = 96.5). Symptomatic focal epilepsy was reported in 62.9% of cases. Mean number of AEDs used in the past was 7.1; mean number of concomitant AEDs was 2.48, with carbamazepine used in 43.5% of patients. Mean PER daily dose was 7.1 mg (2–12 mg). After an average of 6.6 months of follow-up (5–13 months), the retention rate was 77.4% (48/62). The response rate was 50%; 16% of patients achieved ≥75% seizure frequency reduction and 5% became completely seizure free. Seizure aggravation was observed in 9.7% of patients. Adverse events were reported in 19 patients (30.6%) and led to PER discontinuation in 4 patients (6.5%). The most common adverse events were behaviour disturbance (irritability and aggressiveness), dizziness, sedation and fatigue. Conclusion PER was found to be a safe and effective treatment when used as adjunctive therapy in paediatric patients with uncontrolled epilepsy. © 2016 Elsevier B.V.mixedDe Liso, P; Vigevano, F; Specchio, N; De Palma, L; Bonanni, P; Osanni, E; Coppola, G; Parisi, P; Grosso, S; Verrotti, A; Spalice, A; Nicita, F; Zamponi, N; Siliquini, S; Giordano, L; Martelli, P; Guerrini, R; Rosati, A; Ilvento, L; Belcastro, V; Striano, P; Vari, Ms; Capovilla, G; Beccaria, F; Bruni, O; Luchetti, A; Gobbi, G; Russo, A; Pruna, D; Tozzi, Ae; Cusmai, RDe Liso, P; Vigevano, F; Specchio, N; De Palma, L; Bonanni, P; Osanni, E; Coppola, G; Parisi, P; Grosso, Salvatore; Verrotti, A; Spalice, A; Nicita, F; Zamponi, N; Siliquini, S; Giordano, L; Martelli, P; Guerrini, R; Rosati, A; Ilvento, L; Belcastro, V; Striano, P; Vari, Ms; Capovilla, G; Beccaria, F; Bruni, O; Luchetti, A; Gobbi, G; Russo, A; Pruna, D; Tozzi, Ae; Cusmai, R

XIPE: the X-ray imaging polarimetry explorer

X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017 but not selected. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus and two additional GPDs filled with pressurized Ar-DME facing the sun. The Minimum Detectable Polarization is 14 % at 1 mCrab in 10E5 s (2-10 keV) and 0.6 % for an X10 class flare. The Half Energy Width, measured at PANTER X-ray test facility (MPE, Germany) with JET-X optics is 24 arcsec. XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil)