47 research outputs found
2D numerical simulations of earthquake ground motion: examples from the Marche Region, Italy
Exploring the surface of the Moon and Mars: What kind of ground vehicles are required?
On the surface of the Moon and Mars, the astronauts must have at their disposal means for exploring a suitable area of the planet. A ground vehicle was tested for the first time outside Earth during the Apollo program, but the longer stay and the wider extent of the exploration will make similar vehicles designed for Mars larger, faster and more complex. In later missions, transportation on the planet will possibly require aerial vehicles and finally the realization of a whole transportation infrastructure. Furthermore, robotic rovers will be required to assist the astronauts in their exploration duties
Effect of vibrating buildings on “free-field” accelerometric recordings: the Bonefro (Italy) case history
Site Amplification at Permanent Stations in Northeastern Italy
The application of earthquake recordings to the estimation of an event’s magnitude and the construction of rapid-response ground-motion maps requires an adequate classification of the recording stations in terms of their site response. For permanent stations, this information can be obtained from a sufficiently large database of past recordings.In this work, we analyze more than 7300 three-component recordings collected between 1996 and 2017 by 67 permanent stations in northeastern Italy to assess their site amplification.
The signals come from 368 earthquakes with a magnitude range of M 3.2–5.8 and a distance range of 10–300 km. We evaluate the frequency-dependent amplification function with respect to a reference station with a flat seismic noise horizontal-to-vertical spectral ratio. The evaluation relies on the decomposition of the S-wave amplitude spectra in terms of source, propagation, and site response. We solve the decomposition with a nonparametric, single-step generalized inversion in the frequency band 0.5–20 Hz. In addition, we compute the amplification factors for peak ground acceleration and velocity with respect to a well-established ground-motion prediction equation. The results highlight that only 11 stations show a relatively flat unitary response with respect to the reference site, whereas the frequency-averaged amplification function at 23 out of 67 stations exhibits a value larger than 2. We classified the sites according to their surface geology and geo-morphological scenario and found that amplification affects not only stations installed on the alluvial soil but also several stations installed on what are assumed to be rock sites. Sites in caves and mines exhibit deamplification, whereas the stations with sensors in bore-holes exhibit the typical interference pattern. A good correlation between the amplifica tion factors and the frequency-averaged amplification functions suggests the possibility of predicting time-domain peak ground-motion values from amplification functions estimated by generalized inversion
Sexual Abuse Assessment on Admission by Nursing Staff in General Hospital Psychiatric Settings.
OBJECTIVE: Clinicians should have information about patients\u27 sexual abuse history as early as possible, because a history of sexual abuse may affect psychiatric patients\u27 presentation of symptoms and response to treatment. The authors surveyed a nationwide sample of acute inpatient psychiatric facilities to determine whether a history of sexual abuse was completed on admission.
METHODS: A survey questionnaire about current practices relating to assessment of patients\u27 history of sexual abuse was sent to nurse managers at every general hospital in the U.S. that offered inpatient psychiatric services (N = 1,410).
RESULTS: Although respondents at 69 percent of the 466 facilities that participated in the survey believed that the admission assessment of psychiatric patients should always include a history of sexual abuse, only 43 percent of responding facilities included such histories in the admission assessment. Reasons for not including the history included patients\u27 and staff members\u27 unwillingness to discuss sexual abuse, lack of staff competence in discussing the issue, and duplication of data collection that occurs later in the patient\u27s hospital stay.
CONCLUSIONS: Nurse managers of inpatient psychiatric services in general hospitals recognize the importance of including an assessment of patients\u27 history of sexual abuse in the admission assessment but report several obstacles to implementing this procedure
Site response estimation in the Vittorio Veneto area (NE Italy). Part 2: mapping the local seismic effects in the urban settlement
Linear site-specific response spectra for seismic design are defined in the urban area
of Vittorio Veneto (NE Italy) on the basis of the results provided by geological studies,
some geophysical surveys and numerical modelling. The geological survey and the
analysis of the collected stratigraphies located in the Vittorio Veneto basin allowed us
to characterize four soil-types. Geophysical surveys consist of seismic noise
horizontal-to-vertical spectral ratio analysis (HVSR), seismic site response estimated
from earthquake records, S-wave measurements from surface wave dispersion analysis
and inversion, and S-wave velocity from borehole and down-hole measurements. In
addition, a 2-D spectral element method (SPEM 2D) numerical modelling of the
M=5.8, 1936 Cansiglio earthquake was performed along a transect crossing the centre
of Vittorio Veneto in order to assess the influence of the geological structure on the
seismic response of the basin. The procedure followed to define the distribution of the
soil types across the area, the local response spectra and the soil amplification factors
is: 1) soil class identification and definition of the maximum value of the soil factor
(Smax), according to EC8; 2) computation of the amplification coefficients (Sa) from
earthquake and normalized HVSR mean amplitude; 3) zonation of the area into EC8
ground types, with associated elastic response spectra. Since the earthquake dataset
includes only weak events, this study provides only site response estimates for the
linear behaviour. The proposed site response map identifies three narrow zones of
quite high amplification, characterized by C type soils, in Serravalle Vecchia, Vittorio
Veneto centre, and Ceneda
Echolucent femoral plaques entail higher risk of echolucent carotid plaques and a more severe inflammatory profile in peripheral arterial disease.
Effect of Vibrating Buildings on Free-Field Motion and on Adjacent Structures: The Bonefro (Italy) Case History
During the 2002 Molise sequence, a shock was recorded in a building that suffered heavy damage (Mucciarelli et al., 2004). The availability of this data, along with other similar data, led to the organization of an international workshop for structural engineers aimed at the reproduction of the staged evolution of damage observed (A. Goretti and M. Mucciarelli, unpublished manuscript, 2007). The aim of this present work is to model the damaged building; the adjacent, less damaged building; and a large section of the subsoil. The model should provide some insight into two possible phenomena: (1) the soil–structure interaction (SSI), that is, the modification of the free-field seismic response induced by the presence of the buildings located on soft soil; and (2) the possible interaction between the two buildings. The study was performed using the 2D Chebyshev spectral element method (SPEM) for a 2D section. The model, with topography, includes the bedrock (limestone) with the overlaying clay layer, circa 30 m. The building is modeled by an equivalent shearwave velocity, which is calculated from its identified mechanical properties. First, the model’s ability to reproduce the motions recorded inside and outside the building was verified. Then, one or both of the buildings were removed to study their effect. The influence of the presence of buildings on the free-field motion is about 40% on spectral values, and it is felt up to a distance of about 250 m from the buildings. The results also suggest the presence of resonance between buildings