Family <Emphasis Type="Italic">h</Emphasis> of periodic solutions of the restricted problem for big μ

The results of the computation of the family h of symmetric periodic solutions of the circular planar restricted three-body problem for μ = 0.3, 0.4, and 0.5 are presented. This family begins with retrograde circular orbits around a massive body. Associated with each value of μ are the table of critical orbits, the orbit pictures, the graphs of characteristics of the family in four coordinate systems, and the graphs of the period and traces (planar and vertical). Regularities on the family and its evolution as μ increased were observed.     

New gravity maps of the Eastern Alps and significance for the crustal structures

The deep seismic profile Transalp crosses, from north to south, Germany, Austria and Italy. The gravity measurements for each country were made by national agencies with different reference systems and data reduction methods. Within the frame of the Transalp-project a comprehensive database of the Eastern Alps was compiled covering an area of 3.5° by 4° in longitude and latitude (275 by 445 km), respectively. To increase the data coverage in the south Alpine area two gravity surveys were carried out, resulting in 469 areally distributed new stations, of which 215 have been measured with the intent to improve the geoid in the area of the planned Brenner Basistunnel (BBT). The resulting gravity database is the best in terms of resolution and data quality presently available for the Eastern Alps. Here the free air, Bouguer and isostatic gravity fields are critically discussed. The spatial density of existing gravity stations in the three countries is discussed. On the Italian side of the Alps the spatial density is rather sparse compared to the Austrian side. The Bouguer-gravity field varies between − 190 * 10^− 5 m/s² and + 25 * 10^− 5 m/s², with the minimum located along the Alpine high topographic chain, but with a small offset (a few tens of km) to the greatest topographic elevation, showing that the Airy-type local isostatic equilibrium does not fully apply here. The maximum of the Bouguer anomaly has an elongated shape of 100 by 50 km located between the towns of Verona and Vicenza and covers the Venetian Tertiary Volcanic Province (VTVP), a feature not directly related to the plate collision in the Eastern Alps. The gravity high is only partly explainable by high-density magmatic rocks and requires also a deeper source, like a shallowing of the Moho. The isostatic residual anomalies (Airy model) are in the range ± 50 * 10^− 5 m/s², with the greatest positive anomaly corresponding to the location of the VTVP, indicating here under-compensation of masses. At last a discussion of a 2D density model based on reflection seismic data and receiver functions is made.     

Pluri-annual recharge assessment using vertical soil temperature profiles: Example of the Seine river basin (1984–2001)

Among the various methods used to determine vertical water seepage in unsaturated soils, thermal convection presents significant advantages: temperature measurements are simple to perform and record, and a wide range of time scales can be considered. The authors analysed the data recorded by the meteorological stations of the Seine river basin, at three different depths: 20, 50 and 100 cm. As the measurement sensitivity was limited to 0.1 K, long series of data needed to be stacked in order to obtain sufficient precision to quantify the convective component of heat transfer, in a predominantly conductive context. For the period from 1984 to 2001, it was possible to determine the average recharge at each station, and the recharge variation between groups of three-year periods. By interpolating these data over the whole basin, a global assessment has been made and compared to the exported flow rate at the river mouth: the resulting value of 94 mm yr^?1 lies between the lowest annual rate, 52 mm yr^?1, and the mean total exported value of 252 mm yr^?1.     

Structural reworking and heat transfer related to the late-Panafrican Angavo shear zone of Madagascar

The basement of central Madagascar displays two contrasted structural patterns. The first one (D1) is characterized by north-striking foliations that are gently dipping to the west and carry W- to WSW-plunging lineations, whereas the second one (D2) is characterized by steeper foliations that are striking to the NNE and lineations that are either subhorizontal or gently plunging to the SSW. The younger pattern is related to late-Panafrican tectonics along the major Angavo shear zone that is about 1000 km in length and 40 km in width with apparently little offset. Deformation in the Angavo zone induced interference folding on both sides. The D2 event is characterized by low pressures (ca 400 MPa) and high temperatures (up to 790 °C) responsible for prograde granulite facies conditions, that resulted from heat transfer due to magma and fluid advection in the Angavo shear zone. The D2 event is pinned at 550 ± 11 Ma by a new monazite age from a reoriented Andringitrean granite near Ankaramena. A new suite of amphibole and biotite Ar–Ar geochronological data enables to retrace the thermochronogical evolution inside and outside the Angavo shear zone. Combined with new structural results from the western interference zone, these ages yield a better understanding of the late-Panafrican history of central Madagascar. No diachronism is observed along the strike of the Angavo shear zone. Conversely, amphibole and especially biotite ages decrease from West to East, i.e. towards the shear zone. These new ages range from 511 to 469 Ma. A 1-D conductive model constrains the thermal effect in relation with the Angavo shear zone to be restricted to a lateral distance of ca 60 km (in map view) for a maximum heating duration of 20 Myr. This is in agreement with the Ar–Ar data and with the width of the observed interference zone. Following this episode of deformation and heat transfer, the estimated cooling rates of the Angavo shear zone range from to 15 to 6 °C/Myr, respectively before and after 515 Ma. A post-collision intracontinental setting is suggested for the Angavo shear zone, which is regarded as a remote effect of the Kuunga Orogeny between India and Antarctica.     

Effects of non-stoichiometry on the spinel structure at high pressure: Implications for Earth’s mantle mineralogy

A non-stoichiometric sample of spinel with composition ^T(Mg_0.4Al_0.6)^M(Al_1.8□_0.2)O₄ was investigated by single-crystal X-ray diffraction in situ up to about 8.7 GPa using a diamond anvil cell. The P(V) data were fitted using a third-order Birch-Murnaghan equation of state and the unit-cell volume V₀, the bulk modulus K_T0 and its first pressure derivative K′ were refined simultaneously providing the following coefficients: V₀ = 510.34(6) Å³, K_T0 = 171(2) GPa, K′ = 7.3(6). This K_T0 value represents the lowest ever found for spinel crystal structures. Comparing our data with a stoichiometric and natural MgAl₂O₄ (pure composition) we observe a decrease in K_T0 by about 11.5% and a strong increase in K′ by about 33%. These results demonstrate how an excess of Al accompanied by the formation of significant cation vacancies at octahedral site strongly affects the thermodynamic properties of spinel structure. If we consider that the estimated mantle composition is characterized by 3-5% of Al₂O₃ this could imply an Mg/Al substitution with possible formation of cation vacancies. The results of our study indicate that geodynamic models should take into account the potential effect of Mg/Al substitution on the incompressibility of the main mantle-forming minerals (olivine, wadsleyite, ringwoodite, Mg-perovskite).     

Regional modeling of carbonaceous aerosols over Europe—focus on secondary organic aerosols

In this study, an improved and complete secondary organic aerosols (SOA) chemistry scheme was implemented in the CHIMERE model. The implementation of isoprene chemistry for SOA significantly improves agreement between long series of simulated and observed particulate matter concentrations. While simulated organic carbon concentrations are clearly improved at elevated sites by adding the SOA scheme, time correlation are impaired at low level sites in Portugal, Italy and Slovakia. At several sites a clear underestimation by the CHIMERE model is noticed in wintertime possibly due to missing wood burning emissions as shown in previous modeling studies. In Europe, the CHIMERE model gives yearly average SOA concentrations ranging from 0.5 μg m ^− 3 in the Northern Europe to 4 μg m ^− 3 over forested regions in Spain, France, Germany and Italy. In addition, our work suggests that during the highest fire emission periods, fires can be the dominant source of primary organic carbon over the Mediterranean Basin, but the SOA contribution from fire emissions is low. Isoprene chemistry has a strong impact on SOA formation when using current available kinetic schemes.     

Extension of fast periodic transfer orbits from the Earth–Moon RTBP to the Sun–Earth–Moon Quasi-Bicircular Problem

Starting from 80 families of low-energy fast periodic transfer orbits in the Earth–Moon planar circular Restricted Three Body Problem (RTBP), we obtain by analytical continuation 11 periodic orbits and 25 periodic arcs with similar properties in the Sun–Earth–Moon Quasi-Bicircular Problem (QBCP). A novel and very simple procedure is introduced giving the solar phases at which to attempt continuation. Detailed numerical results for each periodic orbit and arc found are given, including their stability parameters and minimal distances to the Earth and Moon. The periods of these orbits are between 2.5 and 5 synodic months, their energies are among the lowest possible to achieve an Earth–Moon transfer, and they show a diversity of circumlunar trajectories, making them good candidates for missions requiring repeated passages around the Earth and the Moon with close approaches to the last.     

On-line recognition of supernova neutrino bursts in the LVD

In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated with a supernova explosion, in the absence of an “external trigger”, e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and intensity at the source.