Innovative Uses of Rain Screen Cladding. CFD and Gas Dispersion Analysis of a Prototype

Abstract In this work, both CFD and CH 4 dispersion analysis in rain screen cladding were carried out, in order to reduce the visual impact of Natural Gas distribution network in civil buildings ensuring high safety standards. In the first part of the work it was conducted the parametric analysis in order to identify the main physical parameters that influence the air velocity in air-gap. Subsequently, CFD simulations were carried out in order to evaluate how the geometric and constructive characteristics can influence the air velocity inside the cavity. In particular, were realized both 2D and 3D models, and was used Ansys Fluent 6.3 software. Finally, Natural Gas dispersion analysis was carried out, in order to evaluate the safety against explosive atmosphere

Systematic review of the safety and efficacy of foam sclerotherapy for venous disease of the lower limbs

Background: Foam sclerotherapy is a potential treatment for lower limb venous disease. Methods: A systematic review, with no restriction on study design, to assess the safety and efficacy of foam sclerotherapy. Results: 69 studies were included. For serious adverse events including pulmonary embolism and deep vein thrombosis, the median event rates were less than 1%. Median rate for visual disturbance was 1.4%. Median rates for some other adverse events were more common, including headache (4.2%), thrombophlebitis (4.7%), matting/skin staining/pigmentation (17.8%) and pain at the site of injection (25.6%). Median rate for complete occlusion of treated veins was 87.0% and for recurrence or development of new veins was 8.1%. Evidence from meta-analysis for complete occlusion suggests that foam sclerotherapy is associated with a lower rate compared with surgery (RR 0.86, 95% CI 0.67 to 1.10) and a higher rate compared with liquid sclerotherapy (RR 1.39, 95% CI 0.91 to 2.11). However, there was substantial heterogeneity across the studies in the meta-analysis. Conclusion: Serious adverse events were rare. There is insufficient evidence to reliably compare the effectiveness of foam sclerotherapy with other minimally invasive therapies or surgery. Evidence from high quality randomised controlled trials is required.This manuscript is based on a systematic review commissioned and funded by the National Institute for Health and Clinical Excellence (NICE) through its Interventional Procedures Programme. The Health Services Research Unit is supported by a core grant from the Chief Scientist Office of the Scottish Executive Health Department

Prevention of Excessive Endothelin-1 Release in Sclerotherapy: In Vitro and In Vivo Studies.

Abstract BACKGROUND The foam sclerotherapy technique has become one of the most commonly used treatments for superficial venous insufficiency. Despite excellent results, few visual/neurologic disturbances have been recently reported; their pathogenesis is still debated but a correlation with endothelin-1 (ET-1) release from the treated vein has been proposed. OBJECTIVE The purpose of this work was to evaluate the ET-1 release after sclerotherapy and to investigate the effects of the anti-endothelin drug aminaphtone. METHODS AND MATERIALS As in vitro sclerotherapy model, an endothelial cell culture, mimicking vascular endothelium, was pretreated with aminaphtone and exposed to detergents. Cell survival and ET-1 release were measured. In in vivo experiments, 45 rats, fed with different aminaphtone-rich diets, were subjected to sclerotherapy, and the systemic ET-1 was measured. RESULTS A minaphtone cell exposure caused a statistically significant reduction in ET-1 release, both before and after in vitro sclerotherapy. Rats fed with aminaphtone showed a trend toward reduced mortality and a significant decrease of ET-1 release after sclerotherapy. CONCLUSION This is the first study in which an anti-endothelin agent was able to cause a significant reduction of ET-1 release during sclerotherapy. Although clinical studies are required, these findings might advocate the use of anti-endothelin agents in prophylaxis of neurologic or visual disturbances after sclerotherapy

On the critical energy required for homogeneous nucleation in bubble chambers employed in dark matter searches

Two equations for the calculation of the critical energy required for homogeneous nucleation in a superheated liquid, and the related critical radius of the nucleated vapour bubble, are obtained, the former by the direct application of the first law of thermodynamics, the latter by considering that the bubble formation implies the overcoming of a barrier of the free enthalpy potential. Comparisons with the currently used relationships demonstrate that the sensitivity of the bubble chambers employed in dark matter searches can be sometimes notably overestimated.Comment: 15 pages, 5 figures, 1 tabl

Effects of the thermodynamic conditions on the acoustic signature of bubble nucleation in superheated liquids used in dark matter search experiments

[EN] In the framework of the search for dark matter in the form of WIMPs using superheated liquids, a study is conducted to establish a computational procedure aimed at determining how the thermodynamic conditions kept inside a particle detector affect the acoustic signal produced by bubble nucleation. It is found that the acoustic energy injected into the liquid by the growing vapour bubble increases as the liquid pressure is decreased and the superheat degree is increased, the former effect being crucial for the generation of a well-intelligible signal. A good agreement is met between the results of the present study and some experimental data available in the literature for the amplitude of the acoustic signal. Additionally, the higher loudness of the alpha-decay events compared with those arising from neutron-induced nuclear recoils is described in terms of multiple nucleations.The authors are grateful to Walter Fulgione for the valuable discussions and suggestions and for his help in reviewing the manuscript.Ardid Ramírez, M.; Baschirotto, A.; Burgio, N.; Corcione, M.; Cretara, L.; De Matteis, L.; Felis-Enguix, I.... (2019). Effects of the thermodynamic conditions on the acoustic signature of bubble nucleation in superheated liquids used in dark matter search experiments. The European Physical Journal C. 79(11):1-9. https://doi.org/10.1140/epjc/s10052-019-7485-xS197911W.J. Bolte et al., Nucl. Instr. Meth. Phys. Res. A 577, 569–573 (2007)E. Behnke et al., Astropart. Phys. 90, 85–92 (2017)M. Felizardo et al., E3S Web Conf. 12, 03002 (2016)E. Behnke et al., Phys. Rev. D 88, 021101 (2013)C. Amole et al., Phys. Rev. Lett. 118, 251301 (2017)A. Antonicci et al., Eur. Phys. J. C 77, 752 (2017)D.A. Glaser, Phys. Rev. 87, 655 (1952)F. Seitz, Phys. Fluids 1, 2–13 (1958)E. Behnke et al., Phys. Rev. Lett. 106, 021303 (2011)D.A. Glaser, D.C. Rahm, Phys. Rev. 97, 474–479 (1955)Yu.N. Martynyuk, N.S. Smirnova, Sov. Phys. Acoust. 37, 376–378 (1991)F. Aubin et al., New J. Phys. 10, 103017 (2008)M. Felizardo et al., Nucl. Instr. Meth. Phys. Res. A 589, 72–84 (2008)P.K. Mondal, B.K. Chatterjee, Phys. Lett. A 375, 237–244 (2011)S. Archambault et al., New J. Phys. 13, 043006 (2011)C. Amole et al., Phys. Rev. Lett. 114, 231302 (2015)R. Sarkar et al., Phys. Lett. A 381, 2531–2537 (2017)I.A. Pless, R.J. Plano, Rev. Sci. Instr. 27, 935–937 (1956)D.V. Bugg, Progr. Nucl. Phys. 7, 2–52 (1959)A. Norman, P. Spiegler, Nucl. Sci. Eng. 16, 213–217 (1963)A.G. Tenner, Nucl. Instr. Meth. 22, 1–42 (1963)Ch. Peyrou, In Bubble and Spark Chambers (Academic Press, New York, 1967)C.R. Bell et al., Nucl. Sci. Eng. 53, 458–465 (1974)G. Bruno et al., Eur. Phys. J. C 79, 183 (2019)B.M. Dorofeev, V.I. Volkova, High Temp. 43, 620–627 (2005)L.D. Landau, E.M. Lifshitz, Fluid Mechanics. Course of Theoretical Physics, vol 6, 2nd edn. (Butterworth-Heinemann, Kidlington, Oxford, 1987)Y.Y. Sun, B.T. Chu, R.E. Apfel, J. Comp. Phys. 103, 126–140 (1992)M.S. Plesset, S.A. Zwick, J. Appl. Phys. 25, 493–500 (1954)L.E. Scriven, Chem. Eng. Sci. 10, 1–13 (1959)H.S. Lee, H. Merte, Int. J. Heat Mass Transf. 39, 2427–2447 (1996)A.J. Robinson, R.L. Judd, Int. J. Heat Mass Transf. 47, 5101–5113 (2004)F. d’Errico, Rad. Prot. Dos. 84, 55–62 (1999)B.B. Mikic, W.M. Rohsenow, P. Griffith, Int. J. Heat Mass Transf. 13, 657–666 (1970)P.J. Linstrom, W.G. Mallard (eds.) NIST Chemistry WebBook, NIST-SRD 69 (National Institute of Standards and Technology, Gaithersburg, MD). https://doi.org/10.18434/T4D303M. Barnabé-Heider et al., Nucl. Instr. Meth. Phys. Res. A 555, 184–204 (2005)D.V. Jordan et al., Appl. Rad. Isot. 63, 645–653 (2005

Linee guida di idrogeologia: approccio ai progetti

Da Cap. Introduzione: Lavorare in idrogeologia significa studiare il moto delle acque sotterranee, la geometria degli acquiferi, la dinamica dell’interazione fra acque sotterranee di differenti acquiferi e fra queste e le acque superficiali; non solo, significa anche comprendere come e perché opere antropiche, sia intenzionalmente che involontariamente, interagiscono con la risorsa acqua e conoscere metodologie e tecniche per progettare in modo ecosostenibile e nel rispetto della risorsa stessa. Nessun progetto di opera che interagisce, intenzionalmente o meno, poco o tanto, con le acque sotterranee può prescindere da un adeguato studio idrogeologico. I capitoli che seguono non pretendono il titolo di manuale, né aspirano a quello di “Bignami” di idrogeologia; le stesse parole “linee guida” presenti nel titolo, lungi dal presumere ogni valore normatorio, hanno solo carattere esplicativo, non una regola, ma piuttosto una traccia, anche perché la “dinamicità” con cui i quadri normativi comunitari, nazionali, regionali e locali si sono recentemente evoluti non permette di confrontarsi con un ambito di leggi e consuetudini collaudato e consolidato. Scopo esclusivo del documento è quello di fornire una guida ai colleghi, liberi professionisti o funzionari che siano, alle prese con la preparazione di studi, relazioni, istruttorie, controlli in materia di risorsa idrica. La prima parte dell’elaborato sintetizza i metodi e gli strumenti dell’idrogeologia (dal rilievo geologico alla geofisica, alla geochimica, ai metodi modellistici), puntualizzando i contenuti indispensabili e opzionali della relazione idrogeologica e della carta idrogeologica; la seconda parte tratta, più specificamente, di normativa e supporto idrogeologico per alcuni selezionati campi di attività (siti inquinati e discariche, viabilità ed infrastrutture lineari, ricerca idrica, pianificazione, attività estrattive). Il documento, privo di qualsiasi pretesa di esaustività sulle problematiche trattate, ha mirato comunque, approfittando della ricchezza di punti di vista derivante dalla vasta gamma di ruoli svolti nella professione dai colleghi della commissione, ad armonizzare le posizioni in un documento tecnico, forse dissonante nello stile, ma univoco negli scopi. Il capitolo 9 “Viabilità ed infrastrutture lineari” tratta del supporto idrogeologico per viabilità, in galleria o meno, di una certa rilevanza regionale; gli stessi approfondimenti, ovviamente tarati sull’importanza dell’opera, sono validi anche per le viabilità Provinciali e Comunali e per le minori. Un accenno a parte per il capitolo 10 “Ricerca idrica ed opere di approvvigionamento idrico” dove è stato ripreso in toto il documento della Commissione Pozzi del 2005, aggiornandolo ed aggiungendo un capitolo relativo alle sorgenti ed un capitolo su problematiche ambientali in cui fra l’altro si è affrontato il critico argomento, purtroppo in Italia ad oggi sottostimato (garbatissimo eufemismo), della definizione, mantenimento e ripristino della separazione fra falde idriche naturalmente distinte. Per quanto concerne le sorgenti, la trattazione tecnico-scientifica è stata privilegiata rispetto a quella burocratico-procedurale, soprattutto perché, nel 90% dei casi, l’iter burocratico per autorizzazioni e concessioni per le sorgenti è identico a quello per i pozzi, alla cui trattazione quindi si rimanda. Riguardo alla Pianificazione (capitolo 11), si è scelto di trattare a grandi linee solo la pianificazione a scala comunale nella Regione Toscana. Il settore pianificazione idrogeologica, che non poteva ovviamente essere omesso in un documento che tratta di idrogeologia, è un settore che in Italia è stato sviluppato, con un certo grado di approfondimento, solo in alcune regioni del nord, regioni che hanno dovuto affrontare gravi emergenze; per il resto, in genere, esso è sempre considerato, quando sia preso in considerazione, come appendice della pianificazione urbanistico-edilizia. La mancanza di norme specifiche in materia rende necessario un approccio di tipo scientifico-tecnico ed una trattazione ben più vasta ed articolata di quella necessaria per semplici linee guida quali sono, o per lo meno vorrebbero essere, quelle che seguono

Cutting-edge R&D activities of CIRTEN in support of the Technology Park annexed to the Italian National Repository of radioactive waste

R&D activities taking place at the institutions belonging to Consorzio Interuniversitario per la Ricerca TEcnologica Nucleare are here presented and discussed. A special focus is on Technology Park annexed to the Italian National Repository of radioactive waste

Comparison and combination of a hemodynamics/biomarkers-based model with simplified PESI score for prognostic stratification of acute pulmonary embolism: findings from a real world study

Background: Prognostic stratification is of utmost importance for management of acute Pulmonary Embolism (PE) in clinical practice. Many prognostic models have been proposed, but which is the best prognosticator in real life remains unclear. The aim of our study was to compare and combine the predictive values of the hemodynamics/biomarkers based prognostic model proposed by European Society of Cardiology (ESC) in 2008 and simplified PESI score (sPESI).Methods: Data records of 452 patients discharged for acute PE from Internal Medicine wards of Tuscany (Italy) were analysed. The ESC model and sPESI were retrospectively calculated and compared by using Areas under Receiver Operating Characteristics (ROC) Curves (AUCs) and finally the combination of the two models was tested in hemodinamically stable patients. All cause and PE-related in-hospital mortality and fatal or major bleedings were the analyzed endpointsResults: All cause in-hospital mortality was 25% (16.6% PE related) in high risk, 8.7% (4.7%) in intermediate risk and 3.8% (1.2%) in low risk patients according to ESC model. All cause in-hospital mortality was 10.95% (5.75% PE related) in patients with sPESI score ≥1 and 0% (0%) in sPESI score 0. Predictive performance of sPESI was not significantly different compared with 2008 ESC model both for all cause (AUC sPESI 0.711, 95% CI: 0.661-0.758 versus ESC 0.619, 95% CI: 0.567-0.670, difference between AUCs 0.0916, p=0.084) and for PE-related mortality (AUC sPESI 0.764, 95% CI: 0.717-0.808 versus ESC 0.650, 95% CI: 0.598-0.700, difference between AUCs 0.114, p=0.11). Fatal or major bleedings occurred in 4.30% of high risk, 1.60% of intermediate risk and 2.50% of low risk patients according to 2008 ESC model, whereas these occurred in 1.80% of high risk and 1.45% of low risk patients according to sPESI, respectively. Predictive performance for fatal or major bleeding between two models was not significantly different (AUC sPESI 0.658, 95% CI: 0.606-0.707 versus ESC 0.512, 95% CI: 0.459-0.565, difference between AUCs 0.145, p=0.34). In hemodynamically stable patients, the combined endpoint in-hospital PE-related mortality and/or fatal or major bleeding (adverse events) occurred in 0% of patients with low risk ESC model and sPESI score 0, whilst it occurred in 5.5% of patients with low-risk ESC model but sPESI ≥1. In intermediate risk patients according to ESC model, adverse events occurred in 3.6% of patients with sPESI score 0 and 6.65% of patients with sPESI score ≥1.Conclusions: In real world, predictive performance of sPESI and the hemodynamic/biomarkers-based ESC model as prognosticator of in-hospital mortality and bleedings is similar. Combination of sPESI 0 with low risk ESC model may identify patients with very low risk of adverse events and candidate for early hospital discharge or home treatment.