Search results for "Fragility"
showing 10 items of 75 documents
Incremental dynamic based fragility assessment of reinforced concrete structures: Stationary vs. non-stationary artificial ground motions
2017
Abstract Artificial and natural records are commonly employed by researches and practitioners to perform refined seismic assessments of structures. The techniques for the generation of artificial records and their effectiveness in producing signals which are significantly representative of real earthquakes are still debated as well as results of the consequent seismic assessment to expect from their application. The paper presents an in-depth comparative study highlighting the effect of employing different typologies of artificial ground motion records on seismic assessment results, especially addressing seismic fragility curves. Three sets of 50 stationary, nonstationary evenly modulated a…
PEM Fuel Cell System Model Predictive Control and real-time operation on a power emulator
2010
Fuel Cell Systems (FCS) seem to be among the most reliable devices to produce clean energy, although they still suffer for many problems, mostly related to the fragility of the Polymer Electrolyte Membrane (PEM). Particularly, this paper focuses on the oxygen starvation, that leads both a decrease of the FCS performance and a shortening in the FCS lifetime. The purpose is to use the Model Predictive Control (MPC) and its capacity of accounting for linear constraints for managing the air system without risking to damage the fuel cell. Two control inputs and no static feed-forward actions have been used. Results show that the MPC is able to avoid the oxygen starvation, even with a sudden incr…
“Houses for One Euro” and the Territory. Some Estimation Issues for the “Geographic Debt” Reduction
2020
The phenomenon of the “houses for one Euro” is the epitome of the progressive and increasing abandonment of the inland territories in which many small towns are affected by continuous and unstoppable depopulation. This process, mostly affecting the southern and insular Italian regions, have been triggered by the quick industrial development started after the second post-war, led by the northern regions, that deeply and irreversibly modified the anthropography of the whole country until now. The impoverishment of a wide part of the Italian territory, is one of the many issues connected to the social-territorial justice that is the original topic by which appraisal and valuation, that is scie…
Why are viral genomes so fragile? The bottleneck hypothesis
2021
If they undergo new mutations at each replication cycle, why are RNA viral genomes so fragile, with most mutations being either strongly deleterious or lethal? Here we provide theoretical and numerical evidence for the hypothesis that genetic fragility is partly an evolutionary response to the multiple population bottlenecks experienced by viral populations at various stages of their life cycles. Modelling within-host viral populations as multi-type branching processes, we show that mutational fragility lowers the rate at which Muller’s ratchet clicks and increases the survival probability through multiple bottlenecks. In the context of a susceptible-exposed-infectious-recovered epidemiolog…
Enhancing Bank Transparency: A Re-assessment
2001
Transparency regulation aims at reducing financial fragility by strengthening market discipline. There are however two elementary properties of banking that may render such regulation inefficient at best and detrimental at worst. First, an extensive financial safety net may eliminate the disciplinary effect of transparency regulation. Second, achieving transparency is costly for banks, as it dilutes their charter values, and hence it also reduces their private costs of risk-taking. We consider both the direct costs of complying with disclosure requirements and the indirect transparency costs stemming from imperfect property rights governing information and specify the conditions under which…
Fragilità e situazioni carcerarie tra circuiti, sezioni protette e diritti negati
2023
Uno sguardo alle funzioni del carcere attraverso la lente della fragilità consente di mettere in luce i limiti dell’attuale sistema penitenziario invitando l’interprete a riflettere su possibili soluzioni per contenerne i noti effetti negativi. L’organizzazione degli spazi, tra circuiti, sezioni e regimi, è espressione di come negli anni sia prevalsa la preoccupazione per la sicurezza, finendo, questa, per assorbire la rieducazione e la tutela di tanti diritti dei detenuti. A look at the functions of the prison through the lens of fragility allows us to highlight the limits of the current penitentiary system, inviting the interpreter to reflect on possible solutions to contain its known neg…
Masonry structures: A proposal of analytical generation of fragility functions for tsunami impact – Application to the Mediterranean coasts
2021
Abstract Evaluation of tsunami vulnerability of coastal buildings is gaining high interest in recent years in the areas with high tsunami hazard. Fragility evaluation is a fundamental step to obtain a quantitative estimation of the probability of building damage and in order to define possible strategies for risk mitigation. Several empirical fragility curves are available for masonry structures. However, an empirical fragility curve is generally based on field surveys after tsunami events, not always available. Conversely, analytical fragility curves are based on prediction approaches. In this paper, a proposal for the evaluation of analytical fragility curves for masonry structures typica…
MAPS. European program case-study. Military assets as public spaces
2019
The call concerns the project experience developed by the research group of Politecnico di Milano - Piacenza Campus – leaded and coordinated by Guya Bertelli (1), as part of the European program MAPS (Military Assets as Public Spaces), supported by URBACT (2), oriented to the development of urban policies. This participation gave the opportunity to the components of the research unit to experiment processes of sharing and examination on the meaning of public space in the contemporary city, mainly in disused and fragile contexts. The project network is composed by 9 cities of as many European countries, with the Municipality of Piacenza as leader: Serres (Greece), Varazdin (Croatia), Szombat…
Crisis, pandemia y fragilidades : reflexiones desde un ?balcón sociológico?.
2020
La crisis derivada de la pandemia por COVID-19 en la que se encuentran nuestras sociedades, nos lleva a pensar en la fragilidad o la incertidumbre como piezas fundamentales de ellas, y a reflexionar sobre las consecuencias sociales de esta situación. La relación cotidiana con una situación de confinamiento a la que nunca antes nos habíamos enfrentado, ha hecho resquebrajarse nuestra forma de gestionar el tiempo, de relacionarnos, de trabajar, de estudiar… Todo ello conllevará un nuevo escenario social en el que se sucederán multitud de preguntas a las que la Sociología deberá dar respuesta al tiempo que soluciones para las consecuencias sociales de esta crisis.
Family studies in scleroderma (systemic sclerosis) demonstrating an HLA-linked increased chromosomal breakage rate in cultured lymphocytes
1988
An increased chromosomal breakage rate (ICBR) was found in 27 of 28 patients with scleroderma (systemic sclerosis, SS) - 5 with the syndrome including calcinosis cutis, Raynaud phenomenon, esophagus hypomotility, sclerodactyly and telangiectasia (CREST), 4 incomplete CREST, 1 overlapping syndrome, 18 progressive systemic sclerosis (PSS). Not only the patients, but also about half of their first-degree relatives showed an increased chromosomal breakage rate (more than 5 breaks per 100 metaphases). This character segregated as a dominant marker in nine families of scleroderma patients. In the six informative of the nine families, the ICBR trait showed close linkage with the HLA region on chro…