Operational modal analysis for the characterization of ancient water towers in Pompeii

In the framework of an investigation campaign carried out in June 2015 by the authors on four ancient water towers (10\u201320 BC) in the archaeological site of Pompeii, modal analysis and output-only identification techniques were employed to extract the dynamic properties in order to assess structural vulnerabilities and support numerical model updating. The four investigated towers (selected among the fourteen present within the archaeological site) are free-standing structures at least 6 m tall, belonging to the Castellum Aquae, i.e. the ancient aqueducts system of the city. During the Roman Age, until the destruction of Pompeii due to the volcanic eruption in 79 AD, water towers provided fresh water to houses, palaces and villas. This particular type of structures are classified as no. 1, 2, 3 and 4 by archaeological literature: no. 1 and 4 are made of soft stone masonry (tuff, limestone), while no. 2 and 3 are composed by brickwork masonry. The paper reports the outcomes of ambient vibration tests performed on four towers in terms of extracted modal parameters using various operational modal analysis techniques. Obtained data are then used to study numerically the soil-structure interaction problem and implement model updating procedures

Calibration of the dynamic behaviour of incomplete structures in archeological sites: The case of Villa Diomede portico in Pompeii

This paper reports the research activities carried out on Villa Diomede in Pompeii, built during the "Pre-Roman period" (i.e. the 3rd century BC) and discovered between 1771 and 1774 during the archaeological excavations. It is one of the greatest private buildings of Pompeii and it is located on the western corner of the modern archeological site. Three levels compose the building: the ground floor, the lower quadriportico with a square plan and a series of colonnades on the four sides around the inner garden and the cryptoportico. Villa Diomede was damaged by the strong earthquake occurred in AD 63 that caused the collapse of the western pillars of the quadriportico and later damaged after the big eruption of Vesuvius in AD 79. In June 2015 a series of nondestructive tests (NDT) were carried out by the authors in order to obtain information on the state of conservation of the building and to assess its structural behavior. Direct and tomographic sonic pulse velocity tests, ground penetrating radar, endoscopies and operational modal analysis were performed on the remaining structural elements on the two levels of the Villa. The present paper reports the main outcomes and findings of ambient vibration tests implemented to extract the modal parameters in terms of eigenfrequencies, mode shapes and damping ratios. Operational modal analysis and output-only identification techniques were applied to single stone pillars of the quadriportico structure and then to the entire square colonnade of Villa Diomede. Results are then used to study the soil-structure interaction at a local level and extend the gained information for the numerical calibration of the whole structure. Thanks to this methodology a detailed model updating procedure of the quadriportico was performed to develop reliable numerical models for the implementation of advance structural and seismic analysis of this "incomplete" archaeological structure

CLIC Muon Sweeper Design

There are several background sources which may affect the analysis of data and detector performans at the CLIC project. One of the important background source is halo muons, which are generated along the beam delivery system (BDS), for the detector performance. In order to reduce muon background, magnetized muon sweepers have been used as a shielding material that is already described in a previous study for CLIC [1]. The realistic muon sweeper has been designed with OPERA. The design parameters of muon sweeper have also been used to estimate muon background reduction with BDSIM Monte Carlo simulation code [2, 3].Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS15), Whistler, Canada, 2-6 November 2015, 7 pages, 6 figure

Studying the coincidence excess between EXPLORER and NAUTILUS during 1998

The coincidences between EXPLORER and NAUTILUS during 1998 (Astone et al. 2001) are more deeply studied. It is found that the coincidence excess is greater in the ten-day period 7-17 September 1998 and it occurs at the sidereal hour 4, when the detectors axes are perpendicular to the Galactic Disk. The purpose of this paper is to bring our results with the GW detectors to the attention of scientists working in the astrophysical field, and ask them whether are they aware of any special phenomenon occurring when EXPLORER and NAUTILUS showed a coincidence excess.Comment: 5 pages, 7 figures, submitted to A &

Efficiency of alternative intensity measures for the seismic assessment of monolithic free-standing columns

This paper deals with the dynamic response of a free-standing ancient column in the Roman Agora of Thessaloniki, Greece as a means to shed more light on the complex behaviour of rocking bodies under seismic excitation. Numerical analyses utilizing discrete element method were carried out with the use of multiple seismic records selected based on the disaggregation of the seismic hazard for the region of interest. To identify their impact on structural performance, earthquake Intensity Measures, such as Peak Ground Acceleration and Peak Ground Velocity are examined for the case of a column that sustained no visible permanent deformations during the Ms = 6.5 Thessaloniki earthquake of 1978. The analysis revealed a weak correlation of PGA and PGV with the response results and a significant influence of the mean frequency (fm) of the seismic motion. No coupling was found between the maximum displacement of the top during the oscillation and the permanent post-seismic deformations. The complementarity of both earthquake Intensity Measures in the structural vulnerability assessment is also depicted

Diferenciação de rochas vulcânicas da formação serra geral utilizando gamaespectrometria terrestre na região vitivinícola Serra Gaúcha, RS - Brasil.

A Região Vitivinícola Serra Gaúcha (RVSG) possui fatores naturais e culturais aliados à geodiversidade da região que implica na formação de solos e relevos diferenciados. Essa particularidade, por sua vez, acarreta em respostas agronômicas específicas da videira e possibilita a valorização da produção de vinhos com distintas qualidades que caracterizam, consequentemente, diferentes terroírs. A área de estudo se situa no contexto de áreas de indicações geográficas para vinhos finos (Vale do Rio das Antas), no limite das unidades geomorfológicas Serra Geral e Planalto dos Campos Gerais, esculpidas sobre rochas da Formação Serra Geral. Na área ocorrem as Fácies Gramado e Caxias. Na primeira, têm-se basaltos de 132 milhões de anos, granulares finos a médios, melanocráticos; na segunda têm-se rochas intermediárias a ácidas (riodacíticas) de 131 milhões de anos, mesocráticas, granulares finas a microfaneríticas. Os horizontes superiores apresentam disjunção tabular bem desenvolvida e as partes centrais dos derrames são maciças, podendo apresentar estruturas de fluxo laminar e dobras. O relevo foi originado na era mesozóica por intenso vulcanismo fissural, havendo platôs com escarpas íngremes e o arcabouço estrutural mostra fraturas e falhas que condicionam a padrões de drenagem angulares e o entalhe das vertentes retilíneas. As áreas cultivadas com vinhedos na RVSG situam-se sobre zonas de maior altitude e menor declividade, relativas aos topos dos platôs, onde predominam rochas ácidas a intermediárias (Fácies Caxias), contendo argissolos, cambissolos e nitossolos. Nas áreas íngremes sobre rochas básicas (Fácies Gramado), ocorrem alissolos e chernossolos situados nos patamares inferiores. O objetivo deste trabalho foi testar um método rápido de distinção de rochas ácidas e básicas, por meio de gamaespectrometria terrestre. As medições foram adquiridas em uma área de 800 Km2 com orientação NE-SW, num perfil transversal da RVSG. O método utilizado empregou o amaespectrometro portátil da marca Radiation Solutíons, modelo super Spec RS-125 de 1024 canais espectrais, cedido pela UNISINOS/NEAP e GPS Garmin Montana 650, sendo o trabalho de campo apoiado pela Embrapa Uva e Vinho. Foram analisadas 83 medidas de rochas, sendo 59 da Fácies Caxias e 24 da Fácies Gramado, em sua maioria de rochas sãs. A classificação dessas rochas foi realizada utilizando critérios descritivos de campo. As medidas de K, eU e eTh foram comparadas na forma de gráficos, relativamente aos valores encontrados na literatura para esses tipos de rochas. Os resultados demonstraram que o método é eficaz na discriminação entre as rochas vulcânicas ácidas e básicas da Formação Serra Geral. Para a Fácies Caxias as concentrações médias foram de 3,7%, 5,5 ppm e 17,4 ppm, para K, eU e eTh, respectivamente. Já para a Fácies Gramado os valores médios de K foram de 2%, de eU foram de 2 ppm e de eTh de 9,2 ppm. O estudo também ratificou que as concentrações de K e eU são mais sensíveis ao grau de intemperismo das rochas do que as concentrações de eTh. Os dados estão organizados em um SIG e, na próxima etapa, o estudo buscará agregar dados de sensoriamento remoto hiperespectral para integrar com os dados gamaespectrométrico e geológicos

Dark Matter searches using gravitational wave bar detectors: quark nuggets and newtorites

Many experiments have searched for supersymmetric WIMP dark matter, with null results. This may suggest to look for more exotic possibilities, for example compact ultra-dense quark nuggets, widely discussed in literature with several different names. Nuclearites are an example of candidate compact objects with atomic size cross section. After a short discussion on nuclearites, the result of a nuclearite search with the gravitational wave bar detectors Nautilus and Explorer is reported. The geometrical acceptance of the bar detectors is 19.5 $\rm m^2$ sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. The experimental limits we obtain are of interest because, for nuclearites of mass less than $10^{-5}$ g, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates. Particles with gravitational only interactions (newtorites) are another example. In this case the sensitivity is quite poor and a short discussion is reported on possible improvements.Comment: published on Astroparticle Physics Sept 25th 2016 replaced fig 1

Quark nuggets search using 2350 Kg gravitational waves aluminum bar detectors

The gravitational wave resonant detectors can be used as detectors of quark nuggets, like nuclearites (nuclear matter with a strange quark). This search has been carried out using data from two 2350 Kg, 2 K cooled, aluminum bar detectors: NAUTILUS, located in Frascati (Italy), and EXPLORER, that was located in CERN Geneva (CH). Both antennas are equipped with cosmic ray shower detectors: signals in the bar due to showers are continuously detected and used to characterize the antenna performances. The bar excitation mechanism is based on the so called thermo-acoustic effect, studied on dedicated experiments that use particle beams. This mechanism predicts that vibrations of bars are induced by the heat deposited in the bar from the particle. The geometrical acceptance of the bar detectors is 19.5 $\rm m^2$ sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. We will show the results of ten years of data from NAUTILUS (2003-2012) and 7 years from EXPLORER (2003-2009). The experimental limits we obtain are of interest because, for nuclearites of mass less than $10^{-4}$ grams, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates.Comment: presented to the 33rd International Cosmic Ray Conference Rio de Janeiro 201

Sistema de informações geográficas como contribuição à utilização de pó de rocha oriundo da formação serra geral em áreas de indicações geográficas vitivinícolas no Brasil.

As áreas de indicação geográfica vitivinícola brasileiras buscam o desenvolvimento sustentável de sua produção e o uso de pó de rocha, bem como práticas de rochagem poderão contribuir para a remineralização dos solos e nutrição de plantas, o que poderá agregar valor ao produto. No entanto, o uso de rochagem é ainda incipiente nas regiões produtoras brasileiras e possivelmente as razões para isto são devidas ao desconhecimento sobre a identificação de fontes destes materiais para rochagem, bem como a distância de transporte destas fontes à área cultivada. A Embrapa Uva e Vinho possui levantamento detalhado da área vitícola das indicações geográficas como Vale dos Vinhedos, Monte Belo, Pinto Bandeira, Altos Montes e Farroupilha, todas localizadas na região vitivinícola Serra Gaúcha, no Estado do Rio Grande do Sul. A Companhia de Pesquisa de Recursos Minerais tem feito extenso levantamento de fontes de agrominerais nos diversos litotipos da Formação Serra Geral no Rio Grande do Sul, definindo materiais que melhor disponibilizam nutrientes para as plantas. No substrato da região vitivinícola Serra Gaúcha ocorrem os Fácies Caxias e Gramado da Formação Serra Geral, os quais possuem variações ao longo dos derrames. Um sistema de informações geográficas foi construído com a finalidade de formar um banco de dados georreferenciado da produção vitivinícola, incluindo as áreas fonte de material para rochagem e, além disto, estabelecendo as distâncias calculadas até as áreas de vinhedos. Foram aplicadas técnicas de geoprocessamento no programa livre gvSIG pelo cruzamento de atributos citados. A área da indicação geográfica Altos Montes, situada nos municípios de Flores da Cunha e Nova Pádua, Rio Grande do Sul, foi investigada a fim de indicar áreas mais favoráveis para obtenção de pó de rocha para ser disponibilizado à viticultura