606 research outputs found

    Detection of low-velocity impact-induced delaminations in composite laminates using Auto-Regressive models

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    In this paper, the detection of delaminations in carbon-fiber-reinforced-plastic (CFRP) laminate plates induced by low-velocity impacts (LVI) is investigated by means of Auto-Regressive (AR) models obtained from the time histories of the acquired responses of the composite specimens. A couple of piezoelectric patches for actuation and sensing purposes are employed. The proposed structural health monitoring (SHM) routine begins with the selection of the suitable locations of the piezoelectric transducers via the numerical analysis of the curvature mode shapes of the CFRP plates. The normalized data recorded for the undamaged plate configuration are then analyzed to obtain the most suitable AR model using five techniques based on the Akaike Information Criterion (AIC), the Akaike Final Prediction Error (FPE), the Partial Autocorrelation Function (PAF), the Root Mean Squared (RMS) of the AR residuals for different order p, and the Singular Value Decomposition (SVD). Linear Discriminant Analysis (LDA) is then applied on the AR model parameters to enhance the performance of the proposed delamination identification routine. Results show the effectiveness of the developed procedure when a reduced number of sensors is available

    The mechanism of iron binding processes in erionite fibres

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    Fibrous erionite-Na from Rome (Oregon, USA) was K-exchanged and characterized from the structural point of view. In addition, the modifications experienced after contact with a Fe(II) source were investigated for evaluating if the large potassium ions, blocking off nearly all the erionite cavity openings, might prevent the Fe(II) binding process, which is currently assumed to be one of the reasons of the toxicity of erionite. The K-exchanged sample had a 95% reduction of the BET surface area indicating that it behaves as a mesoporous material. Exchanged K is segregated at K2 and at OW sites commonly occupied by H2O. The latter K cations provide a relevant contribution to the reduction of the surface area. Surprisingly, despite the collapse of its surface area the sample preserves the tendency to bind Fe(II). Therefore, yet in the case of a peculiar and potentially hostile structural environment the Fe(II) ion-exchange process has essentially the same kinetics observed in a typical erionite sample. This is a clear evidence of the very limited effect of the chemical composition of erionite on the Fe(II) binding process and reasonably it does not play a significant role in its toxicity

    Chapter Caterina Colombini e le origini della congregazione delle gesuate

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    The results of new archival research, compared with some epistles of Blessed Giovanni Colombini, allowed to frame the mystical experience of his cousin Caterina Colombini, which matured in the Sixties of the fourteenth century, in a situation of serious breakdown with his family, caused by patrimonial reasons. Caterina succeeded, also with the help of some friends of her cousin, to free herself from the family context and to constitute the first community of Gesuate, so-called because they observed the same way of life as the Gesuati, then in 1371 to equip this congregation with a residence purchased with her own money in the Sienese district of Vallepiatta and finally to submit it to the protection and jurisdiction of the female Benedictine monastery of Saints Abondio and Abondanzio near Siena. Thus a new female congregation was born, that also spread to other cities in Italy, but it did not turn into a religious order, while avoiding the accusation of heresy for “beguinage”

    Nutritional support in cancer patients: A position paper from the Italian Society of Medical Oncology (AIOM) and the Italian Society of Artificial Nutrition and Metabolism (SINPE)

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    Malnutrition is a frequent problem in cancer patients, which leads to prolonged hospitalization, a higher degree of treatment-related toxicity, reduced response to cancer treatment, impaired quality of life and a worse overall prognosis. The attitude towards this issue varies considerably and many malnourished patients receive inadequate nutritional support. We reviewed available data present in the literature, together with the guidelines issued by scientific societies and health authorities, on the nutritional management of patients with cancer, in order to make suitable and concise practical recommendations for appropriate nutritional support in this patient population. Evidence from the literature suggests that nutritional screening should be performed using validated tools (the Nutritional Risk Screening 2002 [NRS 2002], the Malnutrition Universal Screening Tool [MUST], the Malnutrition Screening Tool [MST] and the Mini Nutritional Assessment [MNA]), both at diagnosis and at regular time points during the course of disease according to tumor type, stage and treatment. Patients at nutritional risk should be promptly referred for comprehensive nutritional assessment and support to clinical nutrition services or medical personnel with documented skills in clinical nutrition, specifically for cancer patients. Nutritional intervention should be actively managed and targeted for each patient; it should comprise personalized dietary counseling and/or artificial nutrition according to spontaneous food intake, tolerance and effectiveness. Nutritional support may be integrated into palliative care programs. "Alternative hypocaloric anti-cancer diets" (e.g. macrobiotic or vegan diets) should not be recommended as they may worsen nutritional status. Well-designed clinical trials are needed to further our knowledge of the nutritional support required in different care settings for cancer patients
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