1,441 research outputs found

    Seismic vulnerability of churches in Faial and Pico islands, Azores

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    Earthquakes represent one of the main cause of serious damage and loss of historic and architectural heritage. Interventions to preserve these building should start with a careful knowledge and assessment of their seismic vulnerability, in order to support any needed retrofitting and strengthening measures. This paper proposes a procedure to register and diagnose of the level of damage on churches after the occurrence of an earthquake, and also to assess the seismic vulnerability of this type of construction. This procedure was applied to sixteen churches in the Azores islands which were hit by the July 9th 1998 earthquake. Belfries of church towers are elements with a particular seismic vulnerability. For this reason, and based on the Italian methodology proposed by the Linee Guida (2006), it is applied to belfries of two churches from Pico (Azores), a simplified mechanical model for assessment of seismic vulnerability of this type of structures

    SIMPLIFIED PARAMETERS FOR THE EVALUATION OF SITE EFFECTS IN THE

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    After the 2002 earthquakes, that struck the southern Italy provinces of Campobasso (Molise) and Foggia (Apulia), the safety assessment of buildings has allowed to evaluate, for different building typologies, the damage level caused by the seismic event; in particular, the survey of the damaged cultural heritage was carried out by the Task Cultural Heritage of the Mixed Operating Centre (COM) in Larino (a village in the epicentral area), coordinated by the “Working Group for the Safeguard of the Cultural Heritage from Natural Risks” (Italy’s Gazzetta Ufficiale n. 116, 21 May 2001 - PCM-DPC Decree, 3 May 2001)”. For this survey activity, the churches were investigated with a specific form proposed by the same Working Group (Ministerial Decree n. 133, 23th January 2001), adopting different forms for other kinds of buildings. The surveyors were organized in teams, called NOPSA (Nuclei Operativi Patrimonio Storico Artistico), composed by officials of the Regional board of the Ministry of Cultural Heritage and Environmental Conservation (architects and art historians), an engineer and a Fire Brigade technician. The first phase of the safety assessment has been developed on the basis of the warnings received by the Larino COM, and most of the surveyed buildings were churches. The damage assessment of public or private buildings began, initially, near the earthquake epicentre (area 1 - IMCS between 6 and 8.5) and subsequently was carried out for all the villages from which inspection requests arrived. At the same time a vulnerability survey was carried out for the churches, using the II level form (Lagomarsino et al., 2004) proposed in the SAVE Project (“Updated Tools for the Seismic Vulnerability Evaluation of the Italian Real Estate and of Urban Systems” – http://gndt.ingv.it). The damage and vulnerability survey has allowed to verify and optimize the procedures for damage assessment immediately after a seismic event (emergency phase) and to obtain useful indications for the reconstruction phase. On the whole 379 monumental buildings in 101 Molise villages and 207 monumental buildings in 44 Apulia villages were investigated. Figure 1 shows the number of monumental buildings surveyed after the earthquakes for each Molise village, subdividing the region according to the seismic classification proposed by the recent Italian Seismic Code (OPCM n. 3274, 2003 – http://zonesismiche.mi.ingv.it)

    3-d visualization and animation of architectonic elements for prehistoric megalithic temples of the island of Gozo: the temple of Ggantija

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    Laser scanning can now be defined without doubt as the newest frontier in the field of survey technique, and recent technological developments of instruments and processing software have encouraged the introduction of this technique in the world of applications connected to archaeological site and other related disciplines. The temple of Ggantija on the island of Gozo was considered to be representative of the entire series of temple complexes due to their particular architectural characteristics, their stage of evolution and form of deterioration, both material and structural. The survey was conducted by the use of the local geodetic network in the different phases: • Topographic survey • 3D laser scanner survey • Photographic Survey: both traditional and digital pictures will be taken in order to fully documentation internal and external surfaces of the site. The treatment and analysis of data collections was divided into the following sub-stages: elaboration and compensation of close polygonal, thickening polygonal and direct measurements; elaboration and compensation of altimetric network; linking of the above data with the existing Maltese national networks; elaboration of laser scanner positions and absolute orientations; elaboration of points coordinates for georeferencing and linking the point clouds coming from laser; final data verification end quality control; analysis of laser measured point clouds, for filtering and subsequent elaboration; scanning orientations and subdivision into “islands” (internal rooms and external sides); analysis of laser measured point clouds over the grid determined by the topographic survey.; modelling of the Archaeological site, elimination of noises and metric "pollution" by statistics and verification; accentuation and reduction of triangles on areas interested by complex geometries; triangles transformation into complex surfaces (mesh); model checking by topographic points; mapping of digital photocolors covering all the surfaces of the site. The digital model will be cut by vertical and horizontal section plans at heights requested by customer 2D graphic editing of the plans, sections and elevations. Finishing of vertical sections (sections and views) using the mapped model created by rendering calculated, generating contours lines from the 3D model; of a light model (low density model) of the laser scanner data using the filtering tools of the software package; of an virtual animation of the high density model; of a mapped VRML (Virtual Reality Modelling Language) model for a web interactive and hypertestual navigation, using the low density model. This part of the study was aimed at defining the architectural characteristics and mode of construction of this monument

    New fully empirical calibrations of strong-line metallicity indicators in star-forming galaxies

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    We derive new empirical calibrations for strong-line diagnostics of gas-phase metallicity in local star-forming galaxies by uniformly applying the Te method over the full metallicity range probed by the Sloan Digital Sky Survey (SDSS). To measure electron temperatures at high metallicity, where the auroral lines needed are not detected in single galaxies, we stacked spectra of more than 110 000 galaxies from the SDSS in bins of log[O ii]/Hβ and log[O iii]/Hβ. This stacking scheme does not assume any dependence of metallicity on mass or star formation rate, but only that galaxies with the same line ratios have the same oxygen abundance. We provide calibrations which span more than 1 dex in metallicity and are entirely defined on a consistent absolute Te metallicity scale for galaxies. We apply our calibrations to the SDSS sample and find that they provide consistent metallicity estimates to within 0.05 dex.MC acknowledges financial support from INAF for his PhD fellowship. RM acknowledges support from the ERC Advanced Grant 695671 "QUENCH'' and support from the Science and Technology Facilities Council (STFC). Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society and the Higher Education Funding Council for England. The SDSS Web Site is http://www.sdss.org/

    Study of the reaction of grafting acrylamide onto xanthan gum

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    AbstractThe present study aimed to study the reaction conditions of grafting of acrylamide on xanthan gum. It was analyzed the influence of reaction conditions, mainly type of initiator activation, initiator concentration and initiator/acrylamide ratio, on graft parameters and copolymer properties. Potassium persulfate was employed as an initiator and heating or N,N,N′,N′-tetramethylethylenediamine was used to activate the initiator. Reaction time and initiator concentration were varied and final values for grafting percentage and grafting efficiency were the same for both methods, whereas speed in reaching these values differs from one technique to another. We found that reaction time was inversely proportional to intrinsic viscosity, likely due to main chain degradation promoted by potassium persulfate (KPS); furthermore, the increasing in the KPS concentration lowers grafting percentage, acrylamide conversion and chain degradation, possibly as a result of O2 formation at high KPS concentrations

    Metodologia para a avaliação da vulnerabilidade sísmica do património religioso: caso de estudo - Faial e Pico, Açores

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    Os sismos representam uma das grandes causas de danos graves e perda do património histórico e arquitectónico. Qualquer intervenção de reabilitação destes edifícios deve partir de uma cuidada avaliação e análise da sua vulnerabilidade sísmica, de modo a desenvolver, se necessário, estratégias de reforço sísmico adequadas. O principal objectivo do presente artigo é estudar a vulnerabilidade sísmica do património religioso das ilhas do Faial e do Pico, nos Açores. Para tal, numa primeira parte deste trabalho, é proposta uma metodologia para o diagnóstico e registo do grau de dano em igrejas após a ocorrência de um sismo, assim como para a avaliação da vulnerabilidade associada a estas. A partir da análise dos danos observados em dezasseis igrejas afectadas pelo sismo de 9 de Julho de 1998 nos Açores, é elaborada uma base de dados que, para além de reunir as características de cada igreja estudada, apoia o cálculo simplificado do índice de dano, vulnerabilidade e coeficiente de segurança global. O campanário das torres sineiras é um elemento particularmente vulnerável aos sismos, devido à sua geometria típica. Por um lado, a existência de grandes aberturas a certos níveis produz tipicamente elementos verticais muito esbeltos. Por outro lado, a elevada concentração de massa no topo das torres também contribui para esta vulnerabilidade. Assim, na segunda parte deste trabalho, é aplicada a metodologia italiana, proposta na Linee Guida per la Valutazione e Reduzione del Rischio Sísmico del Patrimônio Culturale, aos campanários de duas igrejas localizadas na ilha do Pico, com base num modelo mecânico simplificado para a avaliação da vulnerabilidade deste tipo de estruturas. Com o trabalho desenvolvido, pretende-se contribuir para uma sistematização de processos de inspecção e registo de informação relativa a igrejas, com vista a apoiar estratégias de intervenção quer em situações de pós-sismo, quer na mitigação do risco sísmico destas estruturas

    PGE2-Induced IDO1 Inhibits the Capacity of Fully Mature DCs to Elicit an In Vitro Antileukemic Immune Response.

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    In the last years, dendritic cells (DC) have been evaluated for antitumor vaccination. Although DC-based vaccines have raised great expectations, their clinical translation has been largely disappointing. For these results, several explanations have been proposed. In particular, the concomitant expression by DCs of tolerogenic pathways, such as the immunosuppressive agent indoleamine 2,3-dioxygenase-1 (IDO1), has been demonstrated. The aim of this study is to evaluate both the stimulatory and the tolerogenic feature of monocyte-derived DCs (Mo-DCs) after maturation with PGE2. In particular, the role of IDO1 expression in PGE2-matured Mo-DCs has been addressed. Here we show that PGE2, which is required for full maturation of DCs, is one mediator of DC tolerance by enhancing IDO1. PGE2-mediated expression of IDO1 results in the production of kynurenine, in the generation of Tregs, and in the inhibition of either the allogeneic or the autologous antigen-specific stimulatory capacity of DCs. When pulsed with leukemic lysates and matured with PGE2, DCs are impaired in the induction of IFN-γ secreting CD4(+) and CD8(+) T cells due to IDO1 upregulation. Moreover, the inhibition of IDO1 enhances the antileukemic response. Overall, these results point toward the use of IDO1 inhibitors to enhance the vaccination capacity of DCs, matured with PGE2
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