574 research outputs found
Induced seismic-site effects on the vulnerability assessment of a historical centre in the molise Region of Italy: Analysis method and real behaviour calibration based on 2002 earthquake
The present research aims to estimate the influence of site amplification on the seismic vulnerability of the historical centre of the municipality of Baranello in the Molise Region of Italy. Firstly, a structural and typological characterization of the investigated area has been done according to the EMS-98 scale. Subsequently, the vulnerability assessment of the historical buildings located there has been carried out through an appropriate survey form in order to identify the buildings which are most susceptible to seismic damage. To this purpose, the seismic event occurring in October of 2002 has been selected as a reference earthquake. Moreover, according to the AeDES form implemented by the Italian Civil Protection Department to evaluate the usability of constructions after seismic events, the calibration of the typological vulnerability curves of the built-up area has been done, and a quantitative assessment of the local seismic response has been achieved, based on the seismic motions recorded after the 2002 Molise earthquake. Finally, the local amplification factor, which negatively influences the severity of the seismic damage on the structures, has been taken into account in order to more correctly foresee the expected damage of the inspected urban sector, so as to use more appropriately the achieved results for reliable seismic risk mitigation plans
Damage scenario-based approach and retrofitting strategies for seismic risk mitigation: an application to the historical Centre of Sant’Antimo (Italy)
Comparative fragility methods for seismic assessment of masonry buildings located in Muccia (Italy)
The current paper focuses on a sector of the historic centre of Muccia, in the district of Macerata (Italy), affected by the seismic sequence that involved Central Italy in 2016. The main goal is comparison, in terms of fragility curves, among two vulnerability assessment methodologies (empirical and mechanical). The study area has been structurally and typologically identified according to the Building Typology Matrix (BTM). Physical vulnerability analysis of the urban-sector was performed through application of an index-based method, specifically for masonry building aggregates. An isolated masonry building, damaged after the seismic sequences, has been selected as a case study. For the assessed building, empirical fragility curves are presented according to Guagenti & Petrini’s correlation law. Furthermore, a numerical model has been set up by using the macro-element approach, which has allowed to perform non-linear static analyses. Mechanical properties of masonry were defined according to the New Technical Codes for Constructions (NTC18), assuming a limited knowledge level (LC1). Refined mechanical fragility functions have been derived and compared to the empirical ones.
Analysis results have shown that the empirical method tends to overestimate by 5% and 10% the expected damage for slight and moderate thresholds. For PGA values greater than 0,3 g the damage levels decreased by 30% and 20%, with reference to the near collapse and collapse conditions, respectively
Seismic vulnerability assessment of a Romanian historical masonry building under near-source earthquake
In the present research work, the effect of ground motion vertical component in case of near-source excitations on masonry buildings has been analysed. To this purpose, an investigation has been made on the Banloc Castle, a historical masonry construction damaged by the Banat-Voiteg earthquake occurred on December 1991 in the Romanian Region of Banloc. A FEM model of the building, setup using DIANA FEA analysis software, has been analysed in the non-linear dynamic field. In particular, the records have been referred to the Banloc site, characterized by a moment magnitude of 5.5 and a focal depth of 9 km. In order to estimate the influence of the vertical seismic motion on the case study building in terms of both displacement and internal forces, two different scenarios have been examined. The first scenario has taken into account the horizontal component only, whereas the second one has studied the simultaneous effects of three components of the seismic action. The comparison between the two scenarios has shown that the vertical ground motion significantly modifies the structural behaviour of the inspected building. Finally, numerical damage patterns have been plotted and compared to the real cracks detected in the case study after the considered seismic event.(undefined
A behavioral approach to meeting contingency contracting personnel requirements
MBA Professional ReportThis project describes the incentive processes and programs affecting U.S. Army recruitment outcomes in its attempts to encourage civilian participation in deployments for contingency contracting. Major models of human motivation are analyzed in terms of possibilities for improving the shortage of civilian contingency contracting deployments identified by the Gansler Report (October 2007). Issues of incentives, employee needs, motivation, expectations, and deployment concerns, are explored to determine how to increase the quantity and quality of deployable civilians. These issues are organized in accordance with Maslow's Hierarchy of Needs to facilitate a model-based perspective on the Deployable Contingency Contracting Cadre (DCCC) experience. Resultant recommendations include: conduct of an official survey to enhance understanding of the target pool, improvements to the DCCC program which exert maximum control over the forces which affect participation (e.g., a Direct Support Ribbon for participants, DCCC hiring preference points, etc.), and stratification of the DCCC to provide members with a choice of risk levels and associated pay. The researcher also recommends development of distributed contingency contracting support via a "Virtual Contingency Contracting Cadre," whereby the Army's existing technological investments are leveraged to deliver the work capabilities of numerous personnel without the requirements of a physical presence.http://archive.org/details/abehavioralpproa1094510464Approved for public release; distribution is unlimited
Seismic Damage Scenarios Induced by Site Effects of Masonry Clustered Buildings: a South Italy Case Study
The present research aims to investigate the influence of site amplification on the seismic vulnerability of the historical centre of the municipality of Baranello in the Molise Region of Italy. Structural and typological characterization of the investigated area has been done according to the EMS-98 scale. The vulnerability assessment of the historical buildings located there has been carried out through an appropriate survey form in order to identify the buildings most susceptible at seismic damage. Furthermore, according to the AeDES form implemented by the Italian Civil Protection Department, the calibration of the typological vulnerability curves of the built-up area has been done based on the seismic motions recorded after the 2002 Molise earthquake. Finally, the local amplification factor, which negatively influences the severity of the seismic damage on the structures, has been taken into account according to the time-domain method. To this purpose, a refined and simplified approach to
foresee the expected damage of the inspected urban sector has been proposed, so to use more appropriately the achieved results for reliable seismic risk mitigation plans
Effects of balloon injury on neointimal hyperplasia in steptozotocin-induced diabetes and in hyperinsulinemic nondiabetic pancreatic islet-transplanted rats.
BACKGROUND:
The mechanisms of increased neointimal hyperplasia after coronary interventions in diabetic patients are still unknown.
METHODS AND RESULTS:
Glucose and insulin effects on in vitro vascular smooth muscle cell (VSMC) proliferation and migration were assessed. The effect of balloon injury on neointimal hyperplasia was studied in streptozotocin-induced diabetic rats with or without adjunct insulin therapy. To study the effect of balloon injury in nondiabetic rats with hyperinsulinemia, pancreatic islets were transplanted under the kidney capsule in normal rats. Glucose did not increase VSMC proliferation and migration in vitro. In contrast, insulin induced a significant increase in VSMC proliferation and migration in cell cultures. Furthermore, in VSMC culture, insulin increased MAPK activation. A reduction in neointimal hyperplasia was consistently documented after vascular injury in hyperglycemic streptozotocin-induced diabetic rats. Insulin therapy significantly increased neointimal hyperplasia in these rats. This effect of hyperinsulinemia was totally abolished by transfection on the arterial wall of the N17H-ras-negative mutant gene. Finally, after experimental balloon angioplasty in hyperinsulinemic nondiabetic islet-transplanted rats, a significant increase in neointimal hyperplasia was observed.
CONCLUSIONS:
In rats with streptozotocin-induced diabetes, balloon injury was not associated with an increase in neointimal formation. Exogenous insulin administration in diabetic rats and islet transplantation in nondiabetic rats increased both blood insulin levels and neointimal hyperplasia after balloon injury. Hyperinsulinemia through activation of the ras/MAPK pathway, rather than hyperglycemia per se, seems to be of crucial importance in determining the exaggerated neointimal hyperplasia after balloon angioplasty in diabetic animals
Repeat late instent-stenosis after an interval of four years in the same lesion after bare-metal and drug-eluting stent: a case report
In 2001, a 71-year old male was admitted to our hospital with unstable angina. The angiography revealed 2-vessel disease with a 90% stenosis of the proximal LAD. A bare-metal stent was implanted. Four years later the angiography showed a 80% instent-stenosis in the bare-metal stent but no progress at the other coronary arteries. A DES was implanted. Again, four years later, the patient presented with non-ST-elevation myocardial infarction. Angiography showed a 90% instent-restenosis, again without any progession of coronary artery disease in the other vessels. Again a DES implanted. Therefore the processes involved in the late instent-stenosis were not influenced by the antiproliferative agent sirolimu
Seismic Vulnerability Assessment of Romanian Historical Building under Near-Source Earthquake
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Seismic Vulnerability Assessment of Romanian Historical Building under Near-Source Earthquake
The ground motion vertical component is generally ignored in the analysis of ordinary building structures, even though observed damages after last earthquakes highlighted its marked influence especially on the response of masonry structures. In the present research work, the effect of ground motion vertical components in case of near-source excitations has been analysed. The investigation has been made on the Banloc Castle, a historical masonry building damaged by the Banat-Voiteg earthquake occurred on December 1991 in the Region of Banloc in Romania. A FEM model of the building, setup with the DIANA FEA analysis software, has been investigated in the non-linear dynamic field. In particular, the records have been referred to the Banloc site, located 7.01 km far from the epicentre with a moment magnitude Mw=5.5 and a focal depth of 9 km. The behaviour of the ground motion components has been characterised by the V/H peak ground acceleration ratio. In order to estimate the influence of the vertical seismic motion in terms of both displacements and stress regime, two different scenarios have been analysed. The first scenario has taken into account the horizontal component only, whereas the second one has analysed the simultaneous effects of three components of the seismic action. Finally, numerical damage patterns have been plotted aiming to simulate the real cracks detected in the case study after the considered seismic event
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