179,650 research outputs found
Modelling the influence of stress-strain history on the initial shear stiffness of an unsaturated compacted silt.
This is the follow-up paper to Vassallo et al. (2007), which discussed the experimentally observed small-strain behaviour of an unsaturated compacted silt. The influence that suction and, more in general, mean net stress – suction history has on the initial shear stiffness was analysed and ascribed to the accumulation of irreversible volumetric strains. In this study, a model able to predict the observed behaviour is proposed, based on classical unsaturated soil volumetric hardening elastoplastic formulations. Starting from the interpretation of the results relative to simple stress paths, such as preliminary equalization and loading–unloading compression, the results of "complex" stress paths, such as those including drying–wetting cycles, have subsequently been modelled by introducing some additional parameters.Key words: unsaturated, compacted, small strain, stiffness, volumetric behaviour, stress history
Reducing plastic pollution by recovery and recycling: evidence from a ‘Blue Economy’ project impacting policy-making in Italy
: This paper recognizes the relevance of the Seabed Cleaning Project, created by the Angelo Vassallo Sindaco Pescatore Foundation in 2010, and presents it as a tool to achieve benefits in environmental, social, and economic terms, in line with the innovative framework of the Blue Economy. The project suggests a practical, feasible, and scalable solution to plastic pollution that can be obtained thanks to the activity performed by fishermen in cooperation with the municipality and local community (in a multi-level cooperation perspective). The data show a significant reduction of plastic on the seafloor thanks to the project, but further research is needed in order to collect further positive outcomes from different applications of the project. In 2022, the "Salva Mare" Law was approved in the Senate, extending the good practices proposed by the Foundation nationwide and showing how small gestures and concrete actions can provide significant improvements in pursuit of a healthier, safer, greener, and smarter city for the future
The relationship of falls to injury among hospital in-patients
The need to reduce falls is driven by the need to reduce injury. If patients at risk of injury can be distinguished from the patients at risk of falls, there is the potential for a more effective fall risk management policy by targeting injury prevention measures. We conducted a prospective observational study, with blinded endpoint evaluation of 825 consecutive patients admitted to geriatric rehabilitation wards. We identified 150 fallers (18.2%) contributing 243 falls. Fifty-six patients sustained an injury contributing 73 (30.0%) injurious falls. Only five (6.8%) falls resulted in injury of major severity. We identified no significant differences in demographics between injurious and non-injurious falls. A logistic regression analyses of the independent risk factors of suffering an injurious fall were a history of falls (p = 0.036), confusion (p = 0.001) and an unsafe gait (p = 0.03). However, we identified no significant differences in clinical characteristics between patients suffering injurious and non-injurious falls. None of the characteristics studied can identify patients prone to injury after a fall. Injury is largely unpredictable, and more research is needed to determine how injury can be prevented in patients at risk of falls
Statistica Economica con R : : laboratorio di analisi statistica di dati economici tramite software R
Il volume nasce dall'esperienza didattica dell'autore nell'ambito dei corsi di Statistica Economica erogati agli studenti di Statistica all'interno dell'Ateneo di Palermo. Il testo affronta alcuni dei principali temi della Statistica Economica in un approccio applicato con un esteso utilizzo del software open source R, oggi tra i pacchetti statistici in assoluto più diffusi ed utilizzati nelle università e nel mondo del lavoro. Il volume segue un taglio laboratoriale con una presentazione e discussione di alcune tecniche, metodi ed analisi statistiche di specifica utilità per il trattamento del dato economico. Il lettore viene dunque accompagnato durante l'esposizione con continui riferimenti applicati ed ampio utilizzo di dati e script, scaricabili da un sito web dedicato all'interno del quale si trovano anche materiali aggiuntivi ed integrativi rispetto agli argomenti contenuti nel testo. Il libro non usa riferimenti tecnici e metodologici eccessivamente avanzati in modo tale da rendere il contenuto fruibile ad una platea ampia anche con basilari conoscenze economiche e statistiche. I numerosi collegamenti con esempi e casi concreti rende questo progetto editoriale un utile supporto per lo studio dei corsi base e progrediti di Statistica Economica erogati dalle università italiane
Effetti della storia tensionale sulla rigidezza a taglio di un limo costipato parzialmente saturo
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