Autoclavable addition polyimides for 371 C composite applications

Studies were conducted to improve the thermo-oxidative stability (TOS) of PMR type polyimides by the substitution of para-aminostyrene (PAS) for the nadic ester endcap in second generation PMR polyimides (PMR-2). The nadic endcap which provides the PMR polyimides with their relative ease of fabrication, both by limiting the molecular weight of the prepolymer and by undergoing the final addition cure without volatiles, is also the weak link with regard to TOS. A polyimide formulated with PAS endcaps, called V-CAP, utilizes a two step reaction sequence similar to that of the PMR polyimides and can be easily autoclave molded into low void composite materials. Resin studies included two formulations of both PMR-2 and V-CAP, corresponding to n=9 and n=14 prepolymer stoichiometry. Unidirectional reinforced T40R graphite fiber laminates were fabricated from each of the resins was post-cured in either air at 385 C or nitrogen at 400 C. Composite specimens were aged in air at 371 C and mechanical properties were measured at 371 C before and after exposure

Mediastinitis and sternal prosthesis infection successfully treated by minimally invasive omental flap transposition

Purulent mediastinitis is a possible serious complication after mediastinal surgery. We report the case of a localized sternal plasmocytoma treated by sternectomy and prosthetic repair, who needed a second surgery for a fistulizing mediastinitis. Five months earlier, in another Hospital, the patient underwent sternal resection and reconstruction with a “sandwich” prosthesis (Methyl-methacrylate and Marlex mesh). Suppurative mediastinitis occurred and septic shock resolution was observed after the spontaneous opening of a mediastinal cutaneous fistula. After referring to our Unit the patient underwent extensive local and systemic preparation and nutritional support; the infected prosthesis was then removed and the gap filled by a laparoscopically-prepared omental flap. Adequate preoperative management, removal of any infected material and minimally invasive omental flap transposition allowed the successful treatment of this life-threatening condition

Analysis of the tautomeric equilibrium of two red monoazo dyes by UV–Visible, Raman and SERS spectroscopies

Acid Red 26 and Acid Red 18 are two early synthetic dyes belonging to the monazo dye class. The molecular structure of this class of dyes is characterized by the chromophoric azo group (N[dbnd]N) generally attached to benzene or naphthalene derivatives containing electron withdrawing and/or donating groups as substituents. As both red dyes have an OH group in ortho- position respect to the azo group, they undergo an azo-hydrazone tautomerism. In this work, UV–Vis, Raman and SERS spectroscopic analysis of the red dye solutions were carried out at different pH conditions, in order to evaluate the preponderance of one tautomer over the other as a function of the pH. Different experimental conditions were tested in order to find the best ones for the detection of both dyes. Thus, Raman spectra of the powder and aqueous solutions of AR26 and AR18 were obtained at the natural pH of the solutions, and above and below that value. The SERS analysis of the dye solutions were carried out at various pH values between 2 and 10, and with excitation at 442, 532 and 633 nm. The molecular structure and the theoretical Raman spectra of the two tautomers of both red dyes were calculated by DFT methods. The obtained results were used for the assignment of the Acid Red 26 and Acid Red 18 vibrational modes. Finally, a textile sample dyed with AR18 was analyzed by SERS

Production of Electron Neutrinos at Nuclear Power Reactors and the Prospects for Neutrino Physics

High flux of electron neutrinos(\nue) is produced at nuclear power reactors through the decays of nuclei activated by neutron capture. Realistic simulation studies on the neutron transport and capture at the reactor core were performed. The production of \chr51 and \fe55 give rise to mono-energetic \nue's at Q-values of 753 keV and 231 keV and fluxes of $8.3 \times 10^{-4}$ and $3.0 \times 10^{-4}$ \nue/fission, respectively. Using data from a germanium detector at the Kuo-Sheng Power Plant, we derived direct limits on the \nue magnetic moment and the radiative lifetime of \mu_{\nu} < 1.3 \times 10^{-8} ~ \mub and $\rm{\tau_{\nu} / m_{\nu} > 0.11 s / eV}$ at 90% confidence level (CL), respectively. Indirect bounds on $\rm{\tau_{\nu} / m_{\nu}^3}$ were also inferred. The \nue-flux can be enhanced by loading selected isotopes to the reactor core, and the potential applications and achievable statistical accuracies were examined. These include accurate cross-section measurements, studies of mixing angle $\theta_{13}$ and monitoring of plutonium production.Comment: 5 pages, 3 figures, 7 table

On multidimensional poverty rankings of binary attributes

We address the problem of ranking distributions of attributes in terms of poverty, when the attributes are represented by binary variables. To accomplish this task, we identify a suitable notion of “multidimensional poverty line” and characterize axiomatically the Head-Count and the Attribute-Gap poverty rankings, which are the natural counterparts of the most widely used income poverty indices.&nbsp;Finally, we apply our methodology and compare our empirical results with those obtained with some other well-known poverty measures

Quarto rapporto sui fenomeni di criminalità organizzata e corruzione in Toscana. Anno 2019

Questo rapporto approfondisce ed estende, ove possibile fornendo alcune generalizzazioni, i risultati della prima ricognizione sui profili e sulle linee evolutive delle organizzazioni criminali e della corruzione sul territorio toscano a tutto il 2019, in una prospettiva di analisi diacronica che copre anche gli anni precedenti, e fornisce una lettura comparata rispetto alla situazione osservabile in altre regioni italiane – in particolare quelle del centro-Italia – e con i valori medi osservabili sul territorio nazionale. Il rapporto è articolato in due macro-sezioni. La prima parte si concentra sui fenomeni di criminalità organizzata, mediante un’analisi dei processi di espansione criminale in Toscana proponendo degli approfondimenti su alcuni settori-chiave dell’economia toscana, ad elevata vulnerabilità rispetto a questi fenomeni. Un’analisi ad ampio spettro analizza le dinamiche di accesso criminale-mafioso nel ciclo dei contratti pubblici in Toscana. Un altro studio esamina il rapporto tra gioco d’azzardo e criminalità organizzata nella regione in prospettiva comparata con quanto è già emerso in altre realtà territoriali italiane. In un altro capitolo viene proposta la prima mappatura sistematica di gravi forme di sfruttamento lavorativo e caporalato nelle province toscane, con un approfondimento sul distretto di Prato. La seconda parte presenta invece i principali andamenti relativi alla corruzione politica e amministrativa in Toscana attraverso l’utilizzo di statistiche aggiornate, i risultati della content analsys di più di 500 eventi corruttivi nel 2019 (comparati con quelli del biennio precedente), codificati attraverso il progetto C.E.C.O., l’approfondimento analitico e comparato tra i principali eventi intercorsi. La sezione si conclude con una presentazione dei risultati di una ricerca condotta sulla prevenzione della corruzione nel sistema della sanità toscana, attraverso un esame dei PTPC delle aziende del sistema sanitario regionale. In appendice sono altresì fornite informazioni aggiuntive sulla ricerca e catalogazione delle notizie-stampa raccolte, sull’archivio digitale in corso di implementazione

Are the glasses in mantle xenoliths witness of the metasomatic agent composition?

Glass veins and pockets in mantle xenoliths are often considered as indicators of the composition of metasomatic agents affecting the mantle. Here we demonstrate that infiltration of, and reaction with, the host basalt may produce glassy veins and pockets whose composition encompasses that of different potential metasomatic agents. The xenoliths studied are 4-19 cm large, equigranular, spinel-facies harzburgites and lherzolites from the Patagonia lithospheric mantle. A reaction rim occurs at the contact with the basalt. Peridotite orthopyroxene is in reaction with the basalt and a glassy pocket (up to 600 μm in diameter) is thereby formed. New crystals of euhedral olivine (Fo = 84) and Ti-oxides crystallise in the glass pocket close to the basalt, while euhedral crystals of clinopyroxene (mg# = 85-89) and olivine crystallise close to orthopyroxene. The reaction-crystallisation processes induce dramatic compositional variations in theglass pocket from phonotephryte to trachyte. Trace element concentration and patterns and the element anomalies are controlled by the reaction-crystallisation process. Orthopyroxene dissolution has mainly a dilution effect, whereas clinopyroxene crystallisation and the crystallization of Ti oxides (and apatite) largely controls the trace element fractionation and element anomalies. The largest trace element variations are documented in the veins. The studied glasses obviously do not represent metasomatic agents that affected the lithospheric mantle, but the large compositional variations they document encompass those of glasses quoted in literature (Wulff-Pedersen et al., 1996; Coltorti et al., 2000) and believed to represent metasomatic agents, thus suggesting caution in drawing inferences on mantle processes and components from glass pockets and veins in xenoliths

Dynamic titanium prosthesis based on 3D-printed replica for chest wall resection and reconstruction

3D-printing technologies can assist the surgical planning and prosthesis engineering for the management of extended chest wall resection. Different types of prosthesis have been utilized over time, but some concerns remain about their impact on the respiratory function. Here we present a new kind of 3D-printed titanium prosthesis designed to be either strong and flexible. The prosthesis was created on a 1:1 3D-printed anatomic replica of the chest, used to delineate surgical margins and to define the reconstructive requirements