Strong gravitational field light deflection in binary systems containing a collapsed star

Large light deflection angles are produced in the strong gravitational field regions around neutron stars and black holes. In the case of binary systems, part of the photons emitted from the companion star towards the collapsed object are expected to be deflected in the direction of the earth. Based on a semi-classical approach we calculate the characteristic time delays and frequency shifts of these photons as a function of the binary orbital phase. The intensity of the strongly deflected light rays is reduced by many orders of magnitude, therefore making the observations of this phenomenon extremely difficult. Relativistic binary systems containing a radio pulsar and a collapsed object are the best available candidates for the detection of the strongly deflected photons. Based on the accurate knowledge of their orbital parameters, these systems allow to predict accurately the delays of the pulses along the highly deflected path, such that the sensitivity to very weak signals can be substantially improved through coherent summation over long time intervals. We discuss in detail the cases of PSR 1913+16 and PSR 1534+12 and find that the system geometry is far more promising for the latter. The observation of the highly deflected photons can provide a test of general relativity in an unprecedented strong field regime as well as a tight constraint on the radius of the collapsed object.Comment: 7 pages, uuencoded, gzip'ed, postscript file with figures included. Accepted for pubblication in MNRA

The vulnerability assessment of current buildings by a macroseismic approach derived from the EMS-98 scale

A hierarchical family of Damage Probability Matrices (DPM) has been derived in this paper from the ones implicitly contained in the EMS-98 Macroseismic Scale for 6 vulnerability classes. To this aim the linguistic definitions provided by the scale, and the associated fuzzy sub-sets of the percentage of buildings, have been completed according to reliable hypotheses. A parametric representation of the corresponding cumulative probability distributions is moreover provided, through a unique parameter: a vulnerability index variable in the range from 0 to 1 and independent of the macroseismic intensity. Finally, an innovative macroseismic approach allowing the vulnerability analysis of building typologies is defined within the European Macroseismic Scale (EMS-98) and qualitatively related to the vulnerability classes. Bayes’ theorem allows the upgrading of the frequencies when further data about the built-environment or specific properties of the buildings are available, allowing the identification of a different behaviours with respect to the one generally considered for the typology. Fuzzy measures of any damage function can be derived, using parametric or nonparametric damage probability matrices. For every result of the seismic analysis, the procedure allows supply to the user of the final uncertainty connected with the aforementioned fuzzy relation between the probability of the damage grade, the macroseismic intensity and the vulnerability classes

An operational flash-flood forecasting chain applied to the test cases of the EU project HYDROPTIMET

International audience The application of a flash-flood prediction chain, developed by CIMA, to some testcases for the Tanaro river basin in the framework of the EU project HYDROPTIMET is presented here. The components of the CIMA chain are: forecast rainfall depths, a stochastic downscaling procedure and a hydrological model. Different meteorological Limited Area Models (LAMs) provide the rainfall input to the hydrological component. The flash-flood prediction chain is run both in a deterministic and in a probabilistic configuration. The sensitivity of forecasting chain performances to different LAMs providing rainfall forecasts is discussed. The results of the application show how the probabilistic forecasting system can give, especially in the case of convective events, a valuable contribution in addressing the uncertainty at different spatio-temporal scales involved in the flash flood forecasting problem in small and medium basins with complex orography

Metodologia de avaliação da vulnerabilidade sísmica de edifícios antigos à escala do centro histórico

A avaliação do risco sísmico associado aos edifícios existentes está relacionada com a causalidade sísmica local, a vulnerabilidade do edificado e a exposição. A avaliação da vulnerabilidade das construções é especialmente importante na avaliação do risco sísmico, particularmente para edifícios antigos em centros históricos, onde esta poderá ser um factor condicionante para o risco. O grau e o detalhe da avaliação da vulnerabilidade devem ser estabelecidos de acordo com a natureza e o nível de exposição dos edifícios, requerendo-se, tipicamente, um nível mais elevado em edifícios de maior valor patrimonial ou estratégico. A avaliação da vulnerabilidade sísmica dos edifícios existentes na perspectiva da redução do risco associado deve colocar-se não só em relação aos edifícios isolados de relevante importância histórica e cultural, mas também, em relação aos aglomerados de construções antigas em centros urbanos. A análise do desempenho de edifícios em sismos recentemente ocorridos na Europa tem permitido identificar os aspectos estruturais que mais influenciam na vulnerabilidade, e consequentemente nos danos. Propõe-se uma metodologia simplificada para avaliação da vulnerabilidade das construções antigas, e aplica-se a um núcleo urbano histórico, a Baixa de Coimbra. O método proposto, que constitui uma extensão de uma metodologia proposta por outros autores, calcula um índice de vulnerabilidade para cada construção com base em 14 parâmetros. São introduzidos três novos parâmetros na actual proposta. Esta é uma metodologia de primeiro nível, que poderá servir para identificar os edifícios mais vulneráveis do ponto de vista estrutural, que deverão assim ser analisados de forma mais detalhada, com recurso a outras ferramentas mais refinadas. A formulação proposta foi adoptada no estudo da vulnerabilidade sísmica de edifícios em alvenaria do centro urbano de Coimbra. Este estudo é precedido da observação, inspecção e registo de informação detalhada sobre os edifícios, ao nível da caracterização das construções (geometria, tecnologia construtiva, caracterização mecânica das estruturas de alvenaria, etc.) e levantamento de anomalias

Molybdenum sputtering film characterization for high gradient accelerating structures

Technological advancements are strongly required to fulfill the demands of new accelerator devices with the highest accelerating gradients and operation reliability for the future colliders. To this purpose an extensive R&D regarding molybdenum coatings on copper is in progress. In this contribution we describe chemical composition, deposition quality and resistivity properties of different molybdenum coatings obtained via sputtering. The deposited films are thick metallic disorder layers with different resistivity values above and below the molibdenum dioxide reference value. Chemical and electrical properties of these sputtered coatings have been characterized by Rutherford backscattering, XANES and photoemission spectroscopy. We will also present a three cells standing wave section coated by a molybdenum layer $\sim$ 500 nm thick designed to improve the performance of X-Band accelerating systems.Comment: manuscript has been submitted and accepted by Chinese Physics C (2012

Microwave apparatus for gravitational waves observation

In this report the theoretical and experimental activities for the development of superconducting microwave cavities for the detection of gravitational waves are presented.Comment: 42 pages, 28 figure

Seismic vulnerability assessment, damage scenarios and loss estimation: case study of the old city centre of Coimbra, Portugal

The evaluation of the seismic risk of built-up areas is associated to the level of earthquake hazard, building vulnerability and level of exposure. Within this holistic approach that defines seismic risk, building vulnerability is from all three variables, the one that assumes great importance not only because of its obvious physical consequences in the occurrence of a seismic event, but because it is the potential aspect, for which the engineering research can intervene, improve and even control seismic behaviour of existing buildings, reducing the level of vulnerability and consequently the level of physical damage, life loss and economical loss. Development of vulnerability studies in urban centres can be conducted aiming to identify building fragilities and reduce the seismic risk, therefore in the scope of the rehabilitation process of the old city centre of Coimbra, a complete identification and inspection survey of the old masonry buildings has been carried out. The main purpose of this paper is to discuss the vulnerability assessment methodologies, particularly the first level approaches, by presenting a proposed method which determines previously the level of vulnerability, only then assessing physical damage and its relationship to seismic intensity. It is presented and discussed the strategy and proposed methodology adopted for the vulnerability assessment, damage and loss scenarios for the city centre of Coimbra, in Portugal, through the GIS mapping of the building stock of the project perimeter

Applicability of a forecasting chain in a different morphological environment in Italy

International audienceThe operational meteo-hydrological forecasting chain of the Liguria Region (NW Italy) is applied to a different morphoclimatic environment, such as the Emilia Romagna Region (N Italy). Modification to the chain, both in models and in procedures, are introduced to overcome problems related to medium dimension catchments (A?1000km2), characterized by complex altimetry profiles and antropical interventions along the river. The main feature of the original operational procedure, that is the probabilistic approach, is maintained. Hydraulic hazard reduction through artificial reservoirs management is exploited with reference to a specific event occurred on the Reno basin (Emilia Romagna Region)

Evaluation of the surface strength of glass plates shaped by hot slumping process

The Hot Slumping Technology is under development by several research groups in the world for the realization of grazing-incidence segmented mirrors for X-ray astronomy, based on thin glass plates shaped over a mould at temperatures above the transformation point. The performed thermal cycle and related operations might have effects on the strength characteristics of the glass, with consequences on the structural design of the elemental optical modules and consecutively on the entire X-ray optic for large astronomical missions like IXO and ATHENA. The mechanical strength of glass plates after they underwent the slumping process was tested through destructive double-ring tests in the context of a study performed by the Astronomical Observatory of Brera with the collaboration of Stazione Sperimentale del Vetro and BCV Progetti. The entire study has been realized on more than 200 D263 Schott borosilicate glass specimens of dimension 100 mm x 100 mm and thickness 0.4 mm, either flat or bent at a Radius of Curvature of 1000 mm through the particular pressure assisted hot slumping process developed by INAF-OAB. The collected experimental data have been compared to non-linear FEM analyses and treated with Weibull statistic to assess the current IXO glass X-ray telescope design, in terms of survival probability, when subject to static and acoustic loads characteristic of the launch phase. The paper describes the activities performed and presents the obtained results.Comment: Accepted for publication in Optical Enginnering (Jun 26, 2014

Trigger Selection Software for Beauty Physics in ATLAS

The unprecedented rate of beauty production at the LHC will yield high statistics for measurements such as CP violation and Bs oscillation and will provide the opportunity to search for and study very rare decays, such as Bâ ï­ï­ .The trigger is a vital component for this work and must select events containing the channels of interest from a huge background in order to reduce the 40 MHz bunch crossing rate down to 100-200 Hz for recording, of which only a part will be assigned to B-physics. Requiring a single or di-muon trigger provides the first stage of the B-trigger selection. Track reconstruction is then performed in the Inner Detector, either using the full detector, at initial luminosity, or within Regions of Interest identified by the first level trigger at higher luminosities. Based on invariant mass, combinations of tracks are selected as likely decay products of the channel of interest and secondary vertex fits are performed. Events are selected based on properties such as fit quality and invariant mass. We present fast vertex reconstruction algorithms suitable for use in the second level trigger and event filter (level three). We discuss the selection software and the flexible trigger strategies that will enable ATLAS to pursue a B-physics programme from the first running at a luminosity of about 1031 cm-2s-1 through to the design luminosity running at 1034 cm-2s-1