780 research outputs found
Trojan collision probability: a statistical approach
No full textWe study the long term evolution of the collision probability and of the impact velocity vimp in the two Trojan asteroid swarms. The new mathematical formalism by Dell'Oro and Paolicchi (1998) has been used since, in the calculation of the collision probability, it allows to account for the dynamical links among the Trojans and Jupiter orbital angles, due to the 1:1 resonance. This statistical method permits to compute both and vimp over a long timespan (we considered 1 Myr) without making use of heavy numerical integrations. Moreover, it allows to easily update the values of and vimp anytime more complete samples of Trojan orbits are available. The values of and vimp over a short timescale have been compared to those of Marzari et al. (1997) and a good agreement has been observed. Over a long timescale the influence of the secular frequency g5-g6 is clearly visible in . The large oscillations due to the secular frequency are wider for L4 than for L5. We have considered two different initial samples of orbits. The first is the same sample used by Marzari et al. (1997) and includes the orbits of 114 Trojans. The second, more complete, includes 223 objects. We observe an increase of in both the swarms when the more complete sample of Trojan orbits (223) is used. The vimp, instead, slightly decreases compared to the vimp found by Marzari et al. (1997) from the sample of 114 Trojans
Correction to: Size‐Dependent Enforcement, Tax Evasion and Dimensional Trap
No full textThe article “Size‐Dependent Enforcement, Tax Evasion and Dimensional Trap”, written by Raffaella Coppier, Elisabetta Michetti and Luisa Scaccia, was originally published electronically on the publisher’s internet portal on 05 July 2023 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 24 February 2024 to © The Author(s) 2024 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made
Smallsat mission to Didymos: enhanced GNC design for the LICIA science return maximisation
No full textThe interest in near earth objects (NEOs) has widely spread among space agencies during the past decades, not only due to the valuable scientific data these objects can provide, but also for the potential hazard they represent for our planet. In particular, to date there still isn't a validated technique to deflect NEOs on a collision course with Earth. The DART mission, developed by NASA, aims at filling this gap, by testing the effectiveness of a kinetic impactor on the binary asteroid system”Didymos”. In 2022 the spacecraft will hit the smaller asteroid of the binary system, slowing down the moonlet speed with respect to the larger body, permitting the assessment of the impact effectiveness by ground observation measurements. The impact will also generate a cone of ejected particles, of great interest for current numerical impact models validation, which however will be hardly visible from ground. In this context, a bilateral agreement between NASA and Italian Space Agency (ASI) allowed to embark a 6-units CubeSat on DART, called Light Italian Cubesat for Imaging of Asteroids (LICIA). Deployed before the impact, it will fly by the asteroid at the right distance to observe the ejecta evolution and will also be exploited for observation of the asteroid's side not visible from DART, to help estimating the overall volume. The LICIA spacecraft and mission are being developed by ASI through an italian consortium composed by Istituto Nazionale di Astrofisica (INAF), Università di Bologna (UniBo), Argotec, and Politecnico di Milano (PoliMi), respectively covering the fields of mission science and payload, orbit determination, platform development, and mission analysis. The present paper covers the topic of attitude guidance and control design, to ensure the best performance for target pointing during the flyby. The most up-to-date trajectory is taken as baseline scenario to explore various strategies in terms of slew maneuvers to be performed, and optimization for the parameters of the controller. Uncertainties, for the platform and the environment, are introduced to evaluate such strategies in non-nominal, realistic scenarios, with deviations of the trajectory and changes in the flyby distance from the target. Results are compared and the best guidance and control strategy is selected as preliminary baseline. Next steps in the closed-loop architecture development, and related expected issues to be solved, are discussed
Synthetic Images and Colours of the Dimorphos Asteroid Ejecta Plume as seen from the LICIACube spacecraft
No full textIntroductionThe NASA Double Asteroid Redirection Test (DART) mission will be the first test to check an asteroid deflection by a kinetic impactor. The target of DART mission is Dimorphos the secondary element of the (65803) Didymos binary asteroid system, and the impact is expected in late September - early October, 2022 [1] The DART S/C will carry a 6U cubesat called LICIACube (Light Italian Cubesat for Imaging of Asteroid) [2], provided by the Italian Space Agency, with the aim to collect pictures of the impact"s effects. On board LICIAcube will be hosted 2 camera payloads: LEIA a panchromatic (400-900nm Filter, 2.9x2.9° FOV) Narrow Angle Camera and LUKE a RGB (Bayer color filter, 4.8 x 9.15° FOV). LICIACube will be able to acquire the structure and evolution of the DART impact ejecta plume and will obtain high-resolution images and 2 colours data (B-G, G-R) of the surfaces of both bodies and the plume.In order to check the imaging capability and to optimize the fast scientific phase of LICIACube, the LICIACube team performed simulations of pictures" acquisition. In these simulations, considering the specifications of the 2 optical payloads and the foreseen mission design, we reconstructed synthetic images mainly of the plume. Since the study of the plume and its evolution is one of the main scientific goal of the mission we performed a scattering modelling of the ejecta in order to invert the future photometric data deriving hints on the intimate nature of the dust particles released by the impact.Plume simulated Images and column densityWith the two-fold aim of set the operative parameters for the Payloads and to understand the information retrievable by the images of the evolving plume we started an imaging simulation activities taking into account:LICIAcube mission design [3] (Trajectory, Speed, illumination conditions) Payloads optical characteristics The plume evolution was simplified assuming:Non colliding particles during the plume evolution; A speed distribution in the plume given by eq: Where x is the distance on Dimorphos surface from the DART impact point and the other parameters used, considering as main material of asteroid system the cemented basalt, are reported in table:We considered the most representative 3 size bins for what concerns the ejected mass, the expected total number of particles are reported in table:In Figure 1 is reported the simulated image obtained considering the LICIACube trajectory 50s before the close approach (about 110 s after the DART impact).Figure 1 Plume simulated image relative values for irradianceOnce the simulated column density image was obtained, we added a scattering simulation considering spherical dust particles and using a Mie code well suited for large particles approaching the geometric optics regime [4]. In this way we were able to translate column densities in luminous fluxes measured by the instrument using a methodology described in the next section.Plume colours scattering modellingRGB data of the ejecta plume can be used to derive hints on the physical properties of the ejected particles through scattering modelling of the measured two colours (B-G, G-R) and the phase function versus the phase angle of observation α.Given the intensity of solar light incident on the plume"s single particle Iinc,, considering the incident solar light as unpolarized, the intensity of light scattered by the particle at α, Isca is given by [5]:where S11(α) is the first element of the 4X4 scattering Müller matrix, k=2π/λ is the wave number, and r is the distance between the particle and the observer. In this case: being FSun the solar flux at 1 AU, rh the heliocentric distance of the dust particle, and a its radius.The Mie code provides the complete scattering matrix once the dimension of the particle and its composition in terms of the complex refractive index of the material at the considered wavelength are given as input. We used largely referenced laboratory data on basaltic materials to obtain the optical properties of the dust particles [6]. This composition is used to model the dust particles residing on the asteroid surface [1], [2].Then, in order to find the intensity due to the scattering of a single particle measured by the instrument at phase angle α, we convolved Isca with the photometric response of the instrument. For a generic filter, such measured intensity is where Resp is the photometric response of the instrument extended throughout the bandpass of the filter. This response is a known product of several factors as the entrance pupil of the system, the reflectivity of the optics, the transmission curve of the filter, the quantum efficiency of the detector, and the exposure time.Synthetic colours of the dust particles can therefore being computed being the generic color A-B = -2.5log(IA/IB). We performed sample scattering colour calculations varying the particle size from 0.1 micron to 1 cm.Small particles provide extremely variable colours due to the strong influence of scattering resonances being the incident wavelength comparable with the size of the particles themselves. Colours get stable for a larger interval of phase angle proportionally to the increase of the size. Observations of stable colours in the plume during LICIACube flyby will be indicative of particles larger than 100 micron. At the same time, large basalt particles provide a flatter phase function at intermediate and small phase angles than smaller particles.Combined observations of the plume phase function and colour will therefore effectively constrain the size of the ejected particles providing theoretical inputs to the dynamical models
Elisabetta I come Cinzia: Una regina e il suo oceano
No full textThe defeat of the Spanish Armada in the Channel in 1588 turned ‘a weak and feeble woman’ into one of the most relevant characters of late 16th-century European history: Elizabeth I, the Tudor Queen, was considered a semi-divine creature whom the myth, by comparing her to Moon goddesses like Diana and Cinthia, had made known as Semper Eadem.
The identification of the queen with Cinthia became more and more evident after the events occurred in 1588, when she was hailed as the moon goddess par excellence in a series of texts written by her contemporaries. It was in that period, the last decades of the 16th century, that Sir Walter Ralegh, courtier, poet and seaman, wrote The Poems to Cynthia: a collection of short poems where Elizabeth I, the lady of the seas, is addressed as his beloved. The role of Elizabeth as Cinthia is evident above all in Ralegh’s Last Book of the Ocean to Cynthia, an unfinished poem where the author, desperate for being in disgrace, appeals to her clemency and addresses her as the empress of the ocean.La sconfitta della flotta spagnola nelle acque della Manica nel 1588 trasformò una donna sola e fragile in una delle figure più rilevanti della storia europea di fine XVI secolo: Elisabetta I Tudor divenne per i suoi sudditi una creatura semidivina che il mito, accostandola alle divinità lunari Diana e Cinzia, avrebbe consegnato alla Storia come Semper Eadem.
Pur essendo evidente già nei primi tempi del suo regno, l’identificazione della sovrana con Cinzia, la dea che governa i mari e i corsi d’acqua, si fa ancora più evidente dopo il 1588, quando si assiste ad una fioritura di testi che esaltano Elisabetta I come la dea lunare per eccellenza.
Sempre in quegli anni di fine XVI secolo, Sir Walter Ralegh compone The Poems to Cynthia: letterato, cortigiano e uomo di mare, Ralegh dedicherà il suo amore ad Elisabetta come Cinzia, signora dei mari. Il legame tra Elisabetta e l’oceano è soprattutto evidente in Last Book of the Ocean to Cynthia, un poemetto incompiuto in cui il poeta, caduto in disgrazia, riunisce sotto il nome di Cinzia, la donna e la regina, l’amante e la dea, trasformando così Elisabetta in dea e imperatrice dei mari
Elisabetta I come Cinzia. Una regina e il suo oceano.
No full textLa sconfitta della flotta spagnola nelle acque della Manica nel 1588 trasformò una donna sola e fragile in una delle figure più rilevanti della storia europea di fine XVI secolo: Elisabetta I Tudor divenne per i suoi sudditi una creatura semidivina che il mito, accostandola alle divinità lunari Diana e Cinzia, avrebbe consegnato alla Storia come Semper Eadem. Pur essendo evidente già nei primi tempi del suo regno, l’identificazione della sovrana con Cinzia, la dea che governa i mari e i corsi d’acqua, si fa ancora più evidente dopo il 1588, quando si assiste ad una fioritura di testi che esaltano Elisabetta I come la dea lunare per eccellenza. Sempre in quegli anni di fine XVI secolo, Sir Walter Raleigh compone ‘The Poems to Cynthia’: letterato, cortigiano e uomo di mare, Raleigh dedicherà il suo amore ad Elisabetta come Cinzia, signora dei mari. Il legame tra Elisabetta e l’oceano è soprattutto evidente in ‘Last Book of the Ocean to Cynthia’, un poemetto incompiuto in cui il poeta, caduto in disgrazia, riunisce sotto il nome di Cinzia, la donna e la regina, l’amante e la dea, trasformando così Elisabetta in dea e imperatrice dei mari.The defeat of the Spanish Armada in the Channel in 1588 turned ‘a weak and feeble woman’ into one of the most relevant characters of late 16th-century European history: Elizabeth I, the Tudor Queen, was considered a semi-divine creature whom the myth, by comparing her to Moon goddesses like Diana and Cinthia, had made known as Semper Eadem. The identification of the queen with Cinthia became more and more evident after the events occurred in 1588, when she was hailed as the moon goddess par excellence in a series of texts written by her contemporaries. It was in that period, the last decades of the 16th century, that Sir Walter Raleigh, courtier, poet and seaman, wrote ‘The Poems to Cynthia’: a collection of short poems where Elizabeth I, the lady of the seas, is addressed as his beloved. The role of Elizabeth as Cinthia is evident above all in Raleigh’s ‘Last Book of the Ocean to Cynthia’, an unfinished poem where the author, desperate for being in disgrace, appeals to her clemency and addresses her as the empress of the ocean
Praxiphanes of Mytilene (called 'of Rhodes'). The Sources, Text and Translation
No full textNuova edizione dei frammenti di Prassifane di MItilene, detto di Rodi, con traduzione e note. Prassifane era uno dei filosofi di età ellenistica implicato in ruoli anche pubblici in merito ai quali abbiamo segnali di onori ricevuti (cittadinanza e prossenia). I frammenti superstiti permettono di ricostruire la personalità di un filosofo peripatetico, allievo di Teofrasto, che pur avendo acquisito fama come 'primo grammatico' ed essersi occupato di critica letteraria, di poeti, di poetica e di 'storia', non lasciò da parte interessi di etica e probabilmente di fisica. Importante la sua attività a Rodi, nel pieno III sec. a.C., in un periodo nel quale l'isola rivestì un ruolo particolarmente rilevante dal punto di vista politico, economico e culturale per il mondo ellenico.New Critical Edition of the sources related to Praxiphanes of Mytilene, called of Rhodes' (3rd BC), a Peripatetic philosopher, pupil of Theophrastus, whose entire works are lost. The new collection of fragments shows that he was a philosopher involved in public life, called 'first grammarian' and author of works on literary critics, on poetics, on poets, on history, on ethics and physics. He lived and worked in Rhodes in a special period when this island was an important economic, political and cultural centre of the Hellenic world
Embodied Environmental and Social Impacts: A Regionalised Sectoral Method for Low-Carbon Construction Materials in Italy
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Embodied Environmental and Social Impacts: A Regionalised Sectoral Method for Low-Carbon Construction Materials in Italy
by Elisabetta Palumbo 1,* andFrancesco Pomponi 2ORCID
1
Department of Engineering and Applied Science (DISA), University of Bergamo, 24129 Bergamo, Italy
2
York School of Architecture, University of York, York YO10 5DD, UK
*
Author to whom correspondence should be addressed.
Sustainability 2025, 17(21), 9797; https://doi.org/10.3390/su17219797
Submission received: 25 September 2025 / Revised: 26 October 2025 / Accepted: 28 October 2025 / Published: 3 November 2025
(This article belongs to the Topic Construction Project Management and Infrastructure Sustainability)
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Abstract
The decarbonisation of the built environment has increased reliance on Environmental Life Cycle Assessment (E-LCA) to evaluate the impacts of construction materials. However, social aspects—particularly those affecting workers—remain underexplored. This study presents a regionalised approach to support socially and environmentally informed decision-making in the Italian construction sector. For this purpose, we have integrated worker health and safety indicators into the E-LCA of two representative building products assessed across key life cycle stages. These indicators are incorporated into the evaluation of Global Warming Potential (GWP), thus serving as a decision-support tool during the design phase. From a design perspective, the aim is to promote a broader understanding of sustainability—encompassing both environmental and social dimensions—within building projects. Methodologically, the contribution is twofold. First, it addresses the current gap in context-specific data on the critical indicator of worker health and safety in the construction sector, an essential requirement for robust and scientifically recognised S-LCA studies. To this end, the study develops a regionalised scoring system based on publicly available occupational health and safety data from the Italian National Accident Database (INAIL), disaggregated by sector and region. Second, we propose a framework to combine these social indicators with LCA-based environmental impact metrics, which remain central to building-scale E-LCA. It is clear that no single region performs best, while a critical need for multi-criteria decision-making in sustainable design is evident
The Eastern Coast of the Adriatic in the Journals of Elisabetta Caminer
No full textThis paper covers articles dealing with the eastern coast of the Adriatic, i. e. Venetian
Dalmatia and the Dubrovnik Republic, published in L’Europa Letteraria, Giornale
Enciclopedico, Nuovo Giornale Enciclopedico and Nuovo Giornale Enciclopedico d’Italia,
journals which in the second half of the 18th century were edited by the Venetian writer,
journalist and translator Elisabetta Caminer Turra. Her most important contributor for
writings on this region was Alberto Fortis, author of the famous Viaggio in Dalmazia
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