Forma-funzione nella concezione strutturale: il nuovo ponte sul fiume Pescara

Obiettivo di questa Tesi di Laurea è l’approfondimento dei concetti di “forma”, “funzione” e del loro rapporto nella progettazione strutturale

Unambiguous Detection of Reflection in Magnetic Cataclysmic Variables: Joint NuSTAR-XMM-Newton Observations of Three Intermediate Polars

In magnetic cataclysmic variables (CVs), X-ray emission regions are located close to the white dwarf surface, which is expected to reflect a significant fraction of intrinsic X-rays above 10 keV, producing a Compton reflection hump. However, up to now, a secure detection of this effect in magnetic CVs has largely proved elusive because of the limited sensitivity of non-imaging X-ray detectors. Here we report our analysis of joint NuSTAR/XMM-Newton observations of three magnetic CVs, V709 Cas, NY Lup, and V1223 Sgr. The improved hard X-ray sensitivity of the imaging NuSTAR data has resulted in the first robust detection of Compton hump in all three objects, with amplitudes of ~1 or greater in NY Lup, and likely <1.0 in the other two. We also confirm earlier report of a strong spin modulation above 10 keV in V709 Cas, and report the first detection of small spin amplitudes in the others. We interpret this as due to different height of the X-ray emitting region among these objects. A height of ~0.2 white dwarf radii provides a plausible explanation for the low reflection amplitude of V709 Cas. Since emission regions above both poles are visible at certain spin phases, this can also explain the strong hard X-ray spin modulation. A shock height of ~0.05 white dwarf radii can explain our results on V1223 Sgr, while the shock height in NY Lup appears negligible.Comment: 16 pages including 3 figures and 2 tables; accepted for publication in Astrophysical Journal Letter

GRB 980425, SN1998bw and the EMBH model

The EMBH model, previously developed using GRB 991216 as a prototype, is here applied to GRB 980425. We fit the luminosity observed in the 40-700 keV, 2-26 keV and 2-10 keV bands by the BeppoSAX satellite. In addition we present a novel scenario in which the supernova SN1998bw is the outcome of an ``induced gravitational collapse'' triggered by GRB 980425, in agreement with the GRB-Supernova Time Sequence (GSTS) paradigm (Ruffini et al. 2001c). A further outcome of this astrophysically exceptional sequence of events is the formation of a young neutron star generated by the SN1998bw event. A coordinated observational activity is recommended to further enlighten the underlying scenario of this most unique astrophysical system.Comment: 10 pages, 3 figures, in the Proceedings of the 34th COSPAR scientific assembly, Elsevier. Fixed some typos in this new versio

Revealing primary forming techniques in wheel-made ceramics with X-ray microCT

The identification of ceramic forming techniques poses challenges, particularly when different primary and secondary forming techniques are combined, or when specific surface treatments obscure potential diagnostic features. As emphasized in the existing literature, a comprehensive approach should consider all potential sources of information. In this study, we employed a combination of macroscopic observations and X-ray microCT analysis on experimental cups reproduced using the complex technology attested in Middle Bronze Age Crete, i.e. a combination of hand-building technique and potter's wheel. Our investigation focuses on the potential of microCT scanning in unveiling forming techniques in wheel-thrown and wheel-fashioned ceramics. Our results indicate that integrating the visualization of 3D thickness variation in vessel walls, quantification of 2D wall thickness distribution in longitudinal virtual slices, identification of possible structural joints in virtual sections, and evaluation of voids orientation with traditional macroscopic analysis generally allows for the recognition of primary forming techniques and the reconstruction of complex ceramic technological processes

MicroCT imaging of long bones: archaeozoology and domestication from a digital perspective

X-ray microCT imaging offers the possibility to study interior structure of animal remains detecting agerelated changes of bone microstructure. In the present paper we analyse patterns in the development of diaphyseal structure in canids. In particular, the first metacarpal of present-day and archaeological red fox (Vulpes vulpes) and wolf (Canis lupus) individuals have been analysed. Variables describing bone structure were measured by inferring bone development through observation of cross-sections. Results show how bone structure changes through life and how this approach allows to separate young individuals from older ones. This is important both from a zooarchaeological perspective, since microCT imaging is a non-invasive tool to estimate the age at death of animal remains, and to discriminate taxa characterized by a close morphology but different adult body size

Possible stellar asterisms carved on a protohistoric stone

Chisel marks on a stone uncovered in Rupinpiccolo protohistoric hill fort from north-eastern Italy were suggested to be a representation of the night sky (Bernardini et al. 2022 Documenta Praehistorica XLIX). The patterns of the 29 marks are analyzed here to establish if they reproduce popular stellar asterisms. Nine marks are found to match the Tail of Scorpius and five the Orion's Belt, together with Rigel and Betelgeuse. Nine marks are found in the approximate position of the Pleiades showing some match with the cluster members. On the back side, 5 marks possibly reproduce Cassiopeia. One mark slightly North of Orion cannot be identified. The 28 marks show a Pearson correlation coefficient r(28) with stellar positions higher than 0.99 with a probability p of a wrong correlation lower than 0.001. Departures are about one degree, or about 7 mm, as the mean diameter of the marks, which suggests a manufacturing limitation in the charting. The fort dates approximate to 1800-400 BCE when Scorpius and Orion showed about the same orientation at the heliacal rising. The unidentified mark challenges the whole picture. We suggest it could have been the progenitor of a failed supernova, thus offering also the possibility of a verification

GRB970228 as a prototype for short GRBs with afterglow

GRB970228 is analyzed as a prototype to understand the relative role of short GRBs and their associated afterglows, recently observed by Swift and HETE-II. Detailed theoretical computation of the GRB970228 light curves in selected energy bands are presented and compared with observational BeppoSAX data.Comment: 2 pages, 1 figure, to appear in the proceedings of "Swift and GRBs", Venice, 2006, Il Nuovo Cimento, in pres

San Rocco/Koromačnik military camps (2nd–1st centuries BC)

On the San Rocco hill, remote sensing and field-walking campaigns indicated the existence of a large Roman military camp (Camp 1) extending over the whole area, a small camp on the top of the hill (Camp 2), and a large area south of it where orthogonal structures have been identified. To clarify the function and chronology of the remains, three trenches were opened in 2019 and 2021. Part of a terrace construction dated between the end of the 2nd and mid-1st century BC was found in Trench 1. Together with orthogonal crop and shadow marks, it indicates that a large part of the hill was arranged in terraces. The northern rampart of Camp 1 was excavated in Trench 3. The 6.5-m-wide fortification of Phase 1 consisted of four lines of defence combining a low stone wall with a wooden superstructure, protected by a palisade, two lines of wooden obstacles, and a stone escarpment. The structure, dated to the 2nd century BC, was destroyed by a fire and restored by adding an earth bank in Phase 2 (end of the 2nd or beginning of the 1st century BC). Camp 2 on the top of the hill was protected by a low walkway that consisted of an earth rampart reinforced on the inside by a row of stones and on the outside by a stone accumulation (Trench 2). Its construction in Phase 1 is dated into the pre-Caesarean period and the renovation in Phase 2 into the mid-1st century BC