123 research outputs found
Raccolta e modificazione delle conchiglie di Glycymeris nell'Età del Bronzo. Il caso studio di Larda I e Larda II (RO - Italia nord-orientale) [Extraction and modification of Glycymeris shells during the Bronze Age. A case study from Larda I and Larda II (RO – north-east Italy)]
No full textLe prime evidenze della raccolta di conchiglie appartenenti al genere Glycymeris, per la realizzazione di oggetti ornamentali o simbolici, risalgono al Paleolitico medio. Questa tendenza si consolida nel corso del Paleolitico superiore ed è particolarmente frequente nei contesti protostorici dell’Italia settentrionale. Il presente lavoro si propone di indagare le modalità di raccolta e di utilizzo delle conchiglie forate rinvenute nei siti dell’Età del Bronzo di Larda I (Bronzo medio-Bronzo recente)
e Larda II (BR1), localizzati nel Veneto meridionale (Italia nord-orientale). Circa la metà delle conchiglie appartenenti al genere Glycymeris rinvenute nel sito di Larda II presenta un foro in corrispondenza dell’umbone; tuttavia, il cattivo stato di conservazione ha reso difficile l’analisi tracceologica. Particolarmente interessanti sono, invece, i risultati dello studio condotto sulle conchiglie forate provenienti dal sito di Larda I. L’analisi tafonomica ha permesso di riconoscere un’origine naturale per la quasi totalità dei fori, suggerendo uno sfruttamento opportunistico di esemplari naturalmente forati in corrispondenza dell’umbone.The earliest evidence of a deliberate extraction of Glycymeris shells as ornaments or non-utilitarian objects comes from Middle Palaeolithic sites. This trend is well documented during the Upper Palaeolithic and becomes particularly widespread in late prehistoric contexts of Northern Italy. The aim of this study is to investigate the modalities of collection and use of perforated shells from the Bronze Age sites of Larda I (Middle-Recent Bronze Age) and Larda II (BR1), in southern Veneto (Province of Rovigo, north-east Italy). Around half of Glycymeris shells from Larda II are characterised by a perforation at the umbo; nevertheless, the bad state of preservation made usewear
analysis difficult. Particularly interesting are the results of the study conducted on shells with a perforated umbo from the site of Larda I. Taphonomic analysis allowed us to identify a natural origin for almost the totality of the holes, suggesting an opportunistic exploitation of naturally perforated shells
3-D Finite Element Poisson-Nernst-Planck model for the analysis of ion transport across ionic channels
No full textTaphonomy of microshells from Palaeolithic contexts: the case-study of Riparo Bombrini (Balzi Rossi, Ventimiglia, NW Italy)
No full textA 3-D Finite Element Poisson–Nernst–Planck Model for the Analysis of Ion Transport Across Ionic Channels
No full textEngineered combinations of volcanic ash and waste glass for sustainable alkali activated materials
No full textThe environmental sustainability of new materials and production processes is of crucial importance nowadays. This study examines the use of mixtures of volcanic ash collected from street sweeping following pyroclastic eruptions of Mt. Etna, and waste glass fines derived from the recycling process of glass containers, for the manufacturing of dense blocks. These materials can be activated using a low molarity NaOH aqueous solution (3 mol/L) followed by a drying process at 75 °C for 3 days. Additionally, these same mixtures can be used for the preparation of lightweight foams through limited incorporation of sodium perborate and surfactant. The resulting solid products exhibit competitive strength-to-density ratios compared to commercial construction materials. Strength evaluations were conducted using three-point bending tests (0.47–5.93 MPa) and compression tests (7.82–22.77 MPa). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS) reveal a complex hardening mechanism. This mechanism involves unreacted particles that are not strictly bound by gel, resulting from condensation reactions of components released in solution during alkaline attack. Regarding the cold consolidated foams, their morphology may take them suitable for application as sorbents for contaminants as well as thermal insulators (λ = 0.137 W/m·K)
Re: Safety and efficacy concerns of long-acting GnRH agonist trigger for ovulation induction in oncological patients undergoing oocyte cryopreservation: a call for caution and further investigation
No full textRecycling Volcanic Ash and Glass Powder in the Production of Alkali Activated Materials
No full textThe environmental sustainability of new materials and production processes is of crucial importance nowadays. The mechanical properties of a new binder obtained by light activation of waste pozzolanic materials are investigated. The compound consists of volcanic ash from street sweeping after pyroclastic eruptions of Mt. Etna and waste glass fine dust from the recycling process of glass containers. A single component NaOH solution at low molarity (3M) is used. The mechanical strength is determined through of three-point bending tests and compression tests. The results of the performed basic physical and mechanical tests show that the material is promising to be used in the construction field, with compressive strength between 15 and 20 MPa
Impact of the COVID-19 pandemic on voluntary terminations of pregnancy in an Italian metropolitan area
No full textPurpose: The COVID-19 pandemic and national lockdown from 9 March to 4 May 2020 changed social, familial, and sexual relationships, as well as how citizens interact with the health services. How these profound changes have affected sexuality, contraception and voluntary terminations of pregnancy is still largely undescribed. The main objective of this study was therefore to find out whether the COVID-19 pandemic and ensuing lockdown affected the demand for legal abortion. Material and methods: The study period was divided into three phases: the pre-pandemic (January and February 2020); lockdown (March and April); and post-lockdown (May and June). The number and characteristics of women requesting pregnancy termination each month during that time were compared with the stats for the same months in the preceding three years (2017–2019). Results: Immediately after national lockdown, the number of voluntary abortions markedly declined (-40.45%). The effect was more evident in women below 20 years of age (-66.67%), employed versus unemployed women (-42.71% vs. −21.05), and non-Italian versus Italian citizens (-53.01 vs. −32.85). No difference was found in the mean time from request to execution of the procedure, or in the type of the procedure used. Conclusion(s): National lockdown reduced the number of unwanted pregnancies, especially in younger women. The Italian health service’s response to the demand appears to have been unaffected by the pandemic. However, as the demand for abortion is still high, probably due to unplanned pregnancies among cohabitants within a stable relationship, contraception guidance should be improved among women traditionally deemed low-risk in terms of sexual behaviour
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