Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)

The Virgo 3 km interferometer for gravitational wave detection

Virgo, designed, constructed and developed by the French-Italian VIRGO collaboration located in Cascina (Pisa, Italy) and aiming to detect gravitational waves, is a ground-based power recycled Michelson interferometer, with 3 km long suspended Fabry-Perot cavities. The first Virgo scientific data-taking started in mid-May 2007, in coincidence with the corresponding LIGO detectors. The optical scheme of the interferometer and the various optical techniques used in the experiment, such as the laser source, control, alignment, stabilization and detection strategies are outlined. The future upgrades that are planned for Virgo from the optical point of view, especially concerning the evolution of the Virgo laser, are presented. Finally, the next generation of the gravitational wave detector (advanced Virgo) is introduced from the point of view of the laser system

Acute diverticulitis management: evolving trends among Italian surgeons. A survey of the Italian Society of Colorectal Surgery (SICCR)

Acute diverticulitis (AD) is associated with relevant morbidity/mortality and is increasing worldwide, thus becoming a major issue for national health systems. AD may be challenging, as clinical relevance varies widely, ranging from asymptomatic picture to life-threatening conditions, with continuously evolving diagnostic tools, classifications, and management. A 33-item-questionnaire was administered to residents and surgeons to analyze the actual clinical practice and to verify the real spread of recent recommendations, also by stratifying surgeons by experience. CT-scan remains the mainstay of AD assessment, including cases presenting with recurrent mild episodes or women of child-bearing age. Outpatient management of mild AD is slowly gaining acceptance. A conservative management is preferred in non-severe cases with extradigestive air or small/non-radiologically drainable abscesses. In severe cases, a laparoscopic approach is preferred, with a non-negligible number of surgeons confident in performing emergency complex procedures. Surgeons are seemingly aware of several options during emergency surgery for AD, since the rate of Hartmann procedures does not exceed 50% in most environments and damage control surgery is spreading in life-threatening cases. Quality of life and history of complicated AD are the main indications for delayed colectomy, which is mostly performed avoiding the proximal vessel ligation, mobilizing the splenic flexure and performing a colorectal anastomosis. ICG is spreading to check anastomotic stumps' vascularization. Differences between the two experience groups were found about the type of investigation to exclude colon cancer (considering the experience only in terms of number of colectomies performed), the size of the peritoneal abscess to be drained, practice of damage control surgery and the attitude towards colovesical fistula

Measurement of the W-Pair Production Cross Section and W-Decay Branching Fractions in e+e−e^{+}e^{-} Interactions at s\sqrt{s}= 189 GeV

The data collected by the L3 experiment at LEP at a centre-of-mass energy of $188.6~\rm{Ge\kern -0.1em V}$ are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8~pb$^{-1}$. The total cross section for W-pair production, combining all final states, is measured to be $\sigma_{\rm{WW}}= 16.24 \pm 0.37~(stat.) \pm 0.22~(syst.)$~pb. Including our data collected at lower centre-of-mass energies, the hadronic branching fraction of the W-boson is determined to be $B(\rm{W} \rightarrow \rm{qq})= \left[ 68.20 \pm 0.68~(stat.) \pm 0.33~(syst.)\right]~\%$. The results agree with the Standard Model predictions.The data collected by the L3 experiment at LEP at a centre-of-mass energy of 188.6 GeV are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8pb^-1. The total cross section for W-pair production, combining all final states, is measured to be sigma_WW = 16.24 +/- 0.37(stat.) +/- 0.22(syst.) pb. Including our data collected at lower centre-of-mass energies, the hadronic branching fraction of the W-boson is determined to be B(W ->qq) = [68.20 +/- 0.68 (stat.) +/- 0.33 (syst.) ] %. The results agree with the Standard Model predictions.The data collected by the L3 experiment at LEP at a centre-of-mass energy of 188.6 GeV are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8 pb −1 . The total cross section for W-pair production, combining all final states, is measured to be σ WW =16.24±0.37 (stat.)±0.22 (syst.) pb. Including our data collected at lower centre-of-mass energies, the hadronic branching fraction of the W-boson is determined to be B (W→qq)=[68.20±0.68 (stat.)±0.33 (syst.)]%. The results agree with the Standard Model predictions

ARCHITETTURE DELLA LUCE: STRATEGIE DI RECUPERO DEI FARI DELL’ISOLA D’ELBA

Il patrimonio architettonico delle zone costiere italiane può innescare processi di riqualificazione capaci di produrre benefici economici e sociali, in tale ambito assumono un ruolo determinante i fari. Questi sono oggi insidiati da un processo di graduale e lento abbandono causato dalla dif- fusione dalle moderne tecnologie di geo-localizzazione, unite ai sistemi di comando e gestione a distanza che hanno reso superflua la permanenza dei faristi. Non di meno la problematica gestio- ne e manutenzione causata dal ristretto numero di addetti in rapporto al numero elevato di fari, ha avuto come conseguenza che l’Agenzia del Demanio, in sinergia con Difesa Servizi s.p.a., abbia predisposto un sistema di bandi, “Valore Paesi_Fari”, per il loro affidamento e gestione. Questo contributo è la sintesi di una ricerca, tutt’ora in corso, incentrata sullo studio dei fari costieri che, partendo da una classificazione organica e sistematica dei fari necessaria per la forte carenza e frammentarietà delle informazioni disponibili, ha l’obiettivo di sottolinearne l’importanza storica e culturale, individuando le possibili strategie di valorizzazione e le potenzialità di sviluppo, in termini di flessibilità e capacità di adattamento ad una radicale trasformazione funzionale. In que- sta sede si presentano i fari dell’Isola d’Elba per i quali è stato realizzato un quadro conoscitivo dettagliato, grazie al fattivo e prezioso contributo del Comando Marina Nord di La Spezia, che ha generosamente fornito l’imprescindibile supporto logistico e documentale. La ricerca, svi- luppata anche con l’applicazione del HBIM per la fase di conoscenza e del metodo dell’Analisi del Valore, per definire soluzioni progettuali rispondenti a requisiti e limiti economici prefissati, affronta una complessità di tematiche che, in termine di grande sintesi, interessano i rapporti tra l’ambito costiero di riferimento, l’architettura dei fari e le tecniche costruttive in relazione alle diverse culture

Design strategies for the recovery and enhancement of lighthouse: some case studies of the Ligurian Sea

The paper presents the first results of ongoing research analysing some coastal lighthouses in the territorial jurisdiction of the Northern Maritime Command of La Spezia, located between the Island of Elba and the Gulf of La Spezia. The research is inspired by the “Valore Paese - Fari” initiative, launched in 2015 by the Agenzia del Demanio, with Difesa Servizi S.p.a, to promote in the real-estate market several currently disused lighthouses by granting them to overcome the management and maintenance prob-lems. Some of the lighthouses on the Italian coasts are now affected by a gradual abandonment caused by the spread of current geo-localisation technologies and remote control and management systems. The research aims to highlight the historical and cultural importance of lighthouses, identifying possible valorisation strategies and development potential in terms of flexibility and ability to adapt to a radical functional transfor-mation. The article firstly outlines a typological atlas of lighthouses and highlights their technical constructional characteristics. Subsequently, the design strategies of the lighthouses under study are defined for their re-covery and valorisation in compliance with architectural and economic requirements. Starting from an organic and systematic classification that filled the great lack and fragmentation of available information, a detailed survey was carried out using HBIM throughout the knowledge phase, and the Value Analysis method was used to define design solutions that meet pre-established financial requirements and limits. In summary, the research shows how the lighthouse architectures are linked to the coast-al context area, especially to the construction techniques concerning the different local cultures, and can lead to interesting economic and social revitalisation processes of the surrounding areas

Large transport critical currents in unsintered MgB[sub 2] superconducting tapes

The Powder-In-Tube process has been employed to fabricate tape-like conductors with a strong metallic sheath and based on the newly discovered MgB2 superconducting phase. Long superconducting tapes have been prepared by packing reacted MgB2 powders inside pure Ag, Cu and Ni tubes which are then cold worked by drawing and rolling. Such tapes have shown transport properties as good as bulk MgB2 samples sintered in high pressure and high temperature conditions. At 4.2 K, the highest critical current density of 100000 A/cm2 has been achieved on Nickel-sheathed single-filament conductors. A direct correlation between the sheath tensile strength and the critical current of the unsintered tape has been observed.Comment: 9 pages, 3 figures; submitted to Appl. Phys. Lett. Received April 3, 200

Role-based security policies management: a health care example

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro , 7 Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Synthesis, Characterization and Photoactivation Studies on the Novel Pt(IV)-Based [Pt(OCOCH₃)₃(phterpy)] Complex

Photoactivatable Pt(IV) prodrugs represent nowadays an intriguing class of potential metal-based drugs, endowed with more chemical inertness in their oxidized form and better selectivity for the target with respect to the clinically established Pt(II) compounds. In fact, they have the possibility to be reduced by light irradiation directly at the site of interest. For this reason, we synthesized a new Pt(IV) complex, [Pt(OCOCH3)3(4′-phenyl-2,2′:6′,2′′-terpyridine)][CF3SO3] (1), that is well soluble in aqueous medium and totally unreactive towards selected model biomolecules until its reduction. The highlight of this work is the rapid and efficient photoreduction of 1 with visible light (460 nm), which leads to its reactive Pt(II) analogue. This behavior was made possible by taking advantage of an efficient catalytic system based on flavin and NADH, which is naturally present in the cellular environment. As a comparison, the reduction of 1 was also studied with simple UV irradiation, but both UV-Vis spectrophotometry and 1H-NMR spectrometry showed that the flavin-catalyzed reduction with visible light was faster. Lastly, the reactivity against two representative biological targets, i.e., human serum albumin and one monofilament oligonucleotide fragment, was evaluated by high-resolution mass spectrometry. The results clearly pointed out that the prodrug 1 did not interact with these targets until its photoreduction to the Pt(II) analogue