Calibration of the dynamic behaviour of incomplete structures in archeological sites: The case of Villa Diomede portico in Pompeii

This paper reports the research activities carried out on Villa Diomede in Pompeii, built during the "Pre-Roman period" (i.e. the 3rd century BC) and discovered between 1771 and 1774 during the archaeological excavations. It is one of the greatest private buildings of Pompeii and it is located on the western corner of the modern archeological site. Three levels compose the building: the ground floor, the lower quadriportico with a square plan and a series of colonnades on the four sides around the inner garden and the cryptoportico. Villa Diomede was damaged by the strong earthquake occurred in AD 63 that caused the collapse of the western pillars of the quadriportico and later damaged after the big eruption of Vesuvius in AD 79. In June 2015 a series of nondestructive tests (NDT) were carried out by the authors in order to obtain information on the state of conservation of the building and to assess its structural behavior. Direct and tomographic sonic pulse velocity tests, ground penetrating radar, endoscopies and operational modal analysis were performed on the remaining structural elements on the two levels of the Villa. The present paper reports the main outcomes and findings of ambient vibration tests implemented to extract the modal parameters in terms of eigenfrequencies, mode shapes and damping ratios. Operational modal analysis and output-only identification techniques were applied to single stone pillars of the quadriportico structure and then to the entire square colonnade of Villa Diomede. Results are then used to study the soil-structure interaction at a local level and extend the gained information for the numerical calibration of the whole structure. Thanks to this methodology a detailed model updating procedure of the quadriportico was performed to develop reliable numerical models for the implementation of advance structural and seismic analysis of this "incomplete" archaeological structure

Operational modal analysis for the characterization of ancient water towers in Pompeii

In the framework of an investigation campaign carried out in June 2015 by the authors on four ancient water towers (10\u201320 BC) in the archaeological site of Pompeii, modal analysis and output-only identification techniques were employed to extract the dynamic properties in order to assess structural vulnerabilities and support numerical model updating. The four investigated towers (selected among the fourteen present within the archaeological site) are free-standing structures at least 6 m tall, belonging to the Castellum Aquae, i.e. the ancient aqueducts system of the city. During the Roman Age, until the destruction of Pompeii due to the volcanic eruption in 79 AD, water towers provided fresh water to houses, palaces and villas. This particular type of structures are classified as no. 1, 2, 3 and 4 by archaeological literature: no. 1 and 4 are made of soft stone masonry (tuff, limestone), while no. 2 and 3 are composed by brickwork masonry. The paper reports the outcomes of ambient vibration tests performed on four towers in terms of extracted modal parameters using various operational modal analysis techniques. Obtained data are then used to study numerically the soil-structure interaction problem and implement model updating procedures

Can Embeddings Analysis Explain Large Language Model Ranking?

Understanding the behavior of deep neural networks for Information Retrieval (IR) is crucial to improve trust in these effective models. Current popular approaches to diagnose the predictions made by deep neural networks are mainly based on: i) the adherence of the retrieval model to some axiomatic property of the IR system, ii) the generation of free-text explanations, or iii) feature importance attributions. In this work, we propose a novel approach that analyzes the changes of document and query embeddings in the latent space and that might explain the inner workings of IR large pre-trained language models. In particular, we focus on predicting query/document relevance, and we characterize the predictions by analyzing the topological arrangement of the embeddings in their latent space and their evolution while passing through the layers of the network. We show that there exists a link between the embedding adjustment and the predicted score, based on how tokens cluster in the embedding space. This novel approach, grounded in the query and document tokens interplay over the latent space, provides a new perspective on neural ranker explanation and a promising strategy for improving the efficiency of the models and Query Performance Prediction (QPP)

FM22 (Frozen Mitochondria bioassay): an animal alternative bioassay for toxicity measures for water soluble samples.

Several methods have been proposed, using responses of whole organisms. The problem, however, is not only strictly scientific, but also involves cost, resources and time. For example, assay with organisms require expensive testing facilities and long operational times are necessary for toxicity measurements. In order to evaluate potential compound toxicity (acute and sub-chronic), we standardized a bioassay using mitochondria of beef hearth, and their applicability and sensitivity was verified. In respect to other based on mitochondria tests, this bioassay (called FM22) showed unquestionable advantages: i) to freeze mitochondria at -22 °C instead of the classical -80 °C, ii) to perform a very big quantity of biological test using always the same mitochondria pool (avoiding differences from age, sex, or health status depending on different organisms); iii) to identify quickly a tested compounds IC50, easily comparable. FM22 end point is the inhibition of mitochondrial respiratory chain and this event is quantified by oxygen monitoring. The oxygen consumption was measured by a Clark electrode that was interfaced to a PC to collect test analysis data (1200 in 20 Macro, identifiedmin run). A piecewise regression, through an Excel the break point in the oxygen consumption and calculated the toxicity. Blank tests were carried out to verify the oxygen consumption linear fitting. Toxicity tests were performed using pure/mix organic and inorganic compounds, elutriates from sea- and fresh-water sediment, sewage, dissolved burned compound sub-products. The FM22 test was a good predictor of toxicity for water and soluble samples; the bioassay is easy, low cost and rapid, then usable for routine tests or like a part of a battery of ecotoxicological tests

Studio di trattabilità di un sito contaminato da arsenico mediante Pteris vittata

Il presente studio riporta i risultati di una sperimentazione in campo riguardante la fattibilità dell’impiego della specie vegetale Pteris vittata L. per il fitorimedio di un suolo contaminato da arsenico, la Rotonda di San Giuliano a Mestre (VE), caratterizzata da particolari condizioni microambientali e pedologiche. La felce P. vittata è, infatti, una nota iperaccumulatrice di arsenico ed è particolarmente indicata per la fitoestrazione, essendo molto efficiente nella traslocazione di As verso le parti aeree; è una pianta perenne, versatile, resistente, con un’elevata velocità di crescita ed un esteso network di radici e peli radicali. Il sito in esame presenta un suolo di natura limo-argillosa e carenza di sostanza organica umificata. Di conseguenza si ha formazione di crepe e croste superficiali nei periodi secchi, mentre in quelli piovosi si ha rigonfiamento del suolo, perdita di porosità, ristagno d’acqua e l’instaurarsi di condizioni asfittiche locali. Le analisi chimiche condotte sul suolo hanno evidenziato un inquinamento superficiale da arsenico diffuso in tutta l’area, con valore di circa 45 mg∙kg-1, e hanno messo in luce che tutto il contenuto di arsenico è associato agli ossidi/idrossidi di Fe e Mn e quindi potenzialmente biodisponibile in condizioni riducenti. La sperimentazione in campo si è svolta tra l’estate e l’autunno 2007. Nonostante le difficoltà di crescita e sopravvivenza delle piante, dovute alle caratteristiche avverse del suolo e accentuate dalle particolari condizioni microambientali, P. vittata ha mostrato un’elevata capacità di accumulare arsenico. Infatti, a fronte di concentrazioni iniziali pari a circa 4 mg∙kg-1, dopo 105 giorni le concentrazioni misurate nelle fronde erano comprese tra 200 e 900 mg∙kg-1 p.s. con fattori di bioaccumulo compresi tra 4.8 e 20 e fattori di traslocazione circa uguali a 10. I risultati hanno evidenziato la necessità di stabilizzare la struttura del suolo nei riguardi degli sbalzi idrici e migliorare la resistenza di P. vittata mediante l’ottimizzazione delle pratiche agronomiche, anche attraverso l’eventuale utilizzo di piante micorrizate

Phytoremediation potential of the arsenic hyperaccumulator Pteris vittata: preliminary results from a field study

Phytoextraction is a promising technique for the remediation of soils contaminated by metals and metalloids and is proposed as a green alternative to conventional remediation methods. This paper reports the preliminary results of a field study carried out to evaluate the potential of the fern Pteris vittata for the phytoremediation of arsenic polluted sites. P. vittata is a known arsenic hyperaccumulator and its properties have been assessed in a number of studies, mainly at laboratory or glasshouse scale, while few field investigations are reported in the literature. The experimental activity was planned to compare and evaluate the effect of different conditions on plant growth and on as uptake by P. vittata. The study area is located in northeastern Italy. During the experimental period, pedoclimatic conditions were shown to affect strongly plant growth as well as As bioaccumulation. The results of two consecutive field trials confirm the phytoextraction ability of P. vittata under field conditions, but indicate also that the optimization of agronomic practices is crucial for the success of a phytoextraction application at fullscale. The inoculation of ferns with arbuscular mycorrhizal (AM) fungi seems to have a positive influence on plant growth, while its role on phytoextraction efficiency still remains unclear

Human migration: the big data perspective

How can big data help to understand the migration phenomenon? In this paper, we try to answer this question through an analysis of various phases of migration, comparing traditional and novel data sources and models at each phase. We concentrate on three phases of migration, at each phase describing the state of the art and recent developments and ideas. The first phase includes the journey, and we study migration flows and stocks, providing examples where big data can have an impact. The second phase discusses the stay, i.e. migrant integration in the destination country. We explore various data sets and models that can be used to quantify and understand migrant integration, with the final aim of providing the basis for the construction of a novel multi-level integration index. The last phase is related to the effects of migration on the source countries and the return of migrants

Was it Uruguay or Coffee? The causes of the beef jerky industry’s decline in southern Brazil (1850 – 1889)

What caused the decline of the beef jerky’s production in Brazil? The main sustenance for slaves, beef jerky was the most important industry in southern Brazil. Nevertheless, by 1850, producers were already worried that they could not compete with Uruguayan industry. Traditional interpretations impute the decline to labor markets differences in productivity, since Brazil used slaves while Uruguay had abolished slavery in 1842. Recent research also raises the possibility of a Brazilian “Dutch Disease”, resulting from the coffee exports boom. We test both hypothesis and argue that Brazilian production’s decline was associated with structural changes in demand for low quality meat. Trade protection policies created disincentives for Brazilian producers to increase productivity and diversify its cattle industry

Aqueous biphasic hydrogenations catalyzed by rhodium and iridium complexes modified with human serum albumin

Water soluble complexes derived from the interaction between Rh(CO)2(acac) and [Ir(COD)Cl]2, respectively, with human serum albumin (HSA), were employed in the aqueous biphasic hydrogenation of a,b-unsaturated compounds as 2-cyclohexen-1-one (I), 2-butenal (V), 3-phenyl-2-propenal (IX) and 3-aryl-2-methyl-2-propenals (XIII and XVII). Both catalytic systems Rh/HSA and Ir/HSA showed to be very active in the hydrogenation of ketone I even at low temperature and hydrogen pressure; in particular, the rhodium based catalyst showed to be very selective affording exclusively cyclohexanone (II). The a,b-unsaturated aldehydes investigated required higher temperature (up to 60 8C) and pressure (5 MPa) to obtain good conversions. In this case Rh/HSA resulted to bemore active than Ir based catalyst. In all cases both Rh/HSA and Ir/HSA were easily recycled without significant loss of activity