438 research outputs found
Excessive Memory Usage of the ELLPACK Sparse Matrix Storage Scheme throughout the Finite Element Computations
Sparse matrices are occasionally encountered during solution of various problems by means of numerical methods, particularly the finite element method. ELLPACK sparse matrix storage scheme, one of the most widely used methods due to its implementation ease, is investigated in this study. The scheme uses excessive memory due to its definition. For the conventional finite element method, where the node elements are used, the excessive memory caused by redundant entries in the ELLPACK sparse matrix storage scheme becomes negligible for large scale problems. On the other hand, our analyses show that the redundancy is still considerable for the occasions where facet or edge elements have to be used
Charged Droplets in Cryogenic \u3csup\u3e4\u3c/sup\u3eHe Vapor
We have measured the mobility of positive ions in 4He vapor for temperatures between 1.3 and 2.0 K and for saturation ratios between 0.1 and 1.0. We present a model which relates the size of a charged droplet to its mobility and find good quantitative agreement with our data when we calculate the size of the droplet which forms about the ion with classical macroscopic thermodynamic arguments. The radius thus obtained ranges from 7 to 9 Ă…
DETERMINISTIC SCENARIOS AS INPUT MOTION FOR LOSS ASSESSMENT
A predominantly deterministic viewpoint has been adopted for computing seismic ground motion both for urban areas (SP10) and infrastructures loss modeling (SP11) at three selected areas: the cities of Lisbon (Portugal) and Thessaloniki (Greece), and the metropolis of Istanbul (Turkey). The generation of earthquake ground motion scenarios involves both the particular choice of earthquake sources with associated fault rupture parameters, and the ensuing ground motion field calculated by an appropriate numerical tool, or empirically estimated, at a set of selected points within the urban area of interest.
Ground shaking values are predicted for rock conditions and for two distinct frequency bands, i.e. the high frequency range (from 1.0 Hz to 4-5 Hz) in the case of damage evaluation for the vast majority of ordinary building, and the low frequency (≤ 2 Hz) more appropriate for lifeline system damage assessment.
The advanced simulation techniques allowed to properly consider the finite fault effects and directivity, which imply extreme expected values, and they are capable of quantifying the spatial variability of the ground motion near the extended fault
Simulating earthquake scenarios in the European Project LESSLOSS: the case of the metropolitan area of Lisbon (MAL)
In the framework of the ongoing European project “LESSLOSS – Risk Mitigation for Earthquakes and Landslides” two sub-projects are devoted to earthquake disaster scenario predictions and loss modeling for urban areas and infrastructures. This paper is dealing with the sub-project 10, SP10, Task Programme “Scenario earthquake definitions for three cities”. Finite-fault seismological models are proposed to compute the earthquake scenarios for three urban areas – Istanbul (Turkey), Lisbon (Portugal) and Thessaloniki (Greece). For each case study, ground motion scenarios are developed for the most probable two events with different return periods, locations and magnitudes derived from historical and geological data. In this study, we simulate the accelerometric time series and response spectra for high frequency ground motion in the city of Lisbon and surrounding counties (Metropolitan Area of Lisbon), using two possible earthquake models: the inland source area of Lower Tagus Valley, M 5.7 (4.7) and a hypothesis of the offshore source area of the 1755 Lisbon, M 7.6. The non-stationary stochastic method RSSIM (Carvalho et al. 2004) and a new hybrid stochastic-deterministic approach, DSM (Pacor et al., 2005) are used in order to evaluate the ground shaking and to characterize its spatial variability. Then the site effects are evaluated by means of an equivalent stochastic non-linear one-dimensional ground response analysis of stratified soil profile units properly designed. Results are here presented in terms of PGA maps, for offshore and inland scenarios. The mean and worst shaking scenarios for the Metropolitan Area of Lisbon have been delineated at the bedrock. Local effects amplify the synthetic PGA values by approximately a factor of 2. This means that PGA values computed for bedrock in Lisbon city can increase from 0.12g up to 0.25g and up to 0.5g in surroundings, for the inland scenario, and from 0.045g up to 0.090g for a M7.6 offshore scenario
Simulating earthquake scenarios in the European Project LESSLOSS: the case of the metropolitan area of Lisbon (MAL)
In the framework of the ongoing European project “LESSLOSS – Risk Mitigation for Earthquakes and Landslides” two sub-projects are devoted to earthquake disaster scenario predictions and loss modeling for urban areas and infrastructures. This paper is dealing with the sub-project 10, SP10, Task Programme “Scenario earthquake definitions for three cities”. Finite-fault seismological models are proposed to compute the earthquake scenarios for three urban areas – Istanbul (Turkey), Lisbon (Portugal) and Thessaloniki (Greece). For each case study, ground motion scenarios are developed for the most probable two events with different return periods, locations and magnitudes derived from historical and geological data. In this study, we simulate the accelerometric time series and response spectra for high frequency ground motion in the city of Lisbon and surrounding counties (Metropolitan Area of Lisbon), using two possible earthquake models: the inland source area of Lower Tagus Valley, M 5.7 (4.7) and a hypothesis of the offshore source area of the 1755 Lisbon, M 7.6. The non-stationary stochastic method RSSIM (Carvalho et al. 2004) and a new hybrid stochastic-deterministic approach, DSM (Pacor et al., 2005) are used in order to evaluate the ground shaking and to characterize its spatial variability. Then the site effects are evaluated by means of an equivalent stochastic non-linear one-dimensional ground response analysis of stratified soil profile units properly designed. Results are here presented in terms of PGA maps, for offshore and inland scenarios. The mean and worst shaking scenarios for the Metropolitan Area of Lisbon have been delineated at the bedrock. Local effects amplify the synthetic PGA values by approximately a factor of 2. This means that PGA values computed for bedrock in Lisbon city can increase from 0.12g up to 0.25g and up to 0.5g in surroundings, for the inland scenario, and from 0.045g up to 0.090g for a M7.6 offshore scenario
A site-specific earthquake ground response analysis using a fault-based approach and nonlinear modeling. The Case Pente site (Sulmona, Italy)
In this paper we present the ground response analyses (GRA) of a site where an industrial facility is planned. Due
to its location on an active normal fault system known as a relevant seismic gap, the Mt. Morrone Fault system
(MMF), and at the edge of a basin filled with slow velocity continental deposits, a inter-disciplinary and non-
standard approach has been applied to assess the seismic input of the dynamic numerical analyses. It includes
geological, seismological, geotechnical and engineering contributions. Two fault scenarios, MMF1 and MMF2,
were considered and scenario-based (SSHA) and probabilistic (time-dependent, TD, and time-independent, TI)
seismic hazard (PSHA) analyses were implemented. Comparison among the spectra corresponding to the 90th
percentile of the SSHA statistical distribution and the PSHA average ones shows that the SSHA MMF2 has values
similar to the PSHA TD model. The SSHA 90th percentile distribution was selected as target spectra to retrieve the
seismic input for GRA. Nonlinear numerical simulations of seismic wave propagation were implemented to
derive surface ground motion parameters. GRA acceleration response spectra and their PGA are notably higher,
and thus on the side of safety, than those obtained following the Italian code approach for seismic resistant
buildings. These results confirm that a scenario-based methodology can better capture the shaking effect in near-
field conditions, avoiding possibly unconservative underestimations of the seismic actions and in view of a more
robust performance-based approach used by engineers for either new design and/or assessment/retrofit purposes
of the built environment
Stationary State Solutions of a Bond Diluted Kinetic Ising Model: An Effective-Field Theory Analysis
We have examined the stationary state solutions of a bond diluted kinetic
Ising model under a time dependent oscillating magnetic field within the
effective-field theory (EFT) for a honeycomb lattice . Time evolution of
the system has been modeled with a formalism of master equation. The effects of
the bond dilution, as well as the frequency and amplitude of
the external field on the dynamic phase diagrams have been discussed in detail.
We have found that the system exhibits the first order phase transition with a
dynamic tricritical point (DTCP) at low temperature and high amplitude regions,
in contrast to the previously published results for the pure case \cite{Ling}.
Bond dilution process on the kinetic Ising model gives rise to a number of
interesting and unusual phenomena such as reentrant phenomena and has a
tendency to destruct the first-order transitions and the DTCP. Moreover, we
have investigated the variation of the bond percolation threshold as functions
of the amplitude and frequency of the oscillating field.Comment: 8 pages, 4 figure
European lipodystrophy registry: Background and structure
Background: Lipodystrophy syndromes comprise a group of extremely rare and heterogeneous diseases characterized by a selective loss of adipose tissue in the absence of nutritional deprivation or catabolic state. Because of the rarity of each lipodystrophy subform, research in this area is difficult and international co-operation mandatory. Therefore, in 2016, the European Consortium of Lipodystrophies (ECLip) decided to create a registry for patients with lipodystrophy. Results: The registry was build using the information technology Open Source Registry System for Rare Diseases in the EU (OSSE), an open-source software and toolbox. Lipodystrophy specific data forms were developed based on current knowledge of typical signs and symptoms of lipodystrophy. The platform complies with the new General Data Protection Regulation (EU) 2016/679 by ensuring patient pseudonymization, informational separation of powers, secure data storage and security of communication, user authentication, person specific access to data, and recording of access granted to any data. Inclusion criteria are all patients with any form of lipodystrophy (with the exception of HIV-associated lipodystrophy). So far 246 patients from nine centres (Amsterdam, Bologna, Izmir, Leipzig, M\ufcnster, Moscow, Pisa, Santiago de Compostela, Ulm) have been recruited. With the help from the six centres on the brink of recruitment (Cambridge, Lille, Nicosia, Paris, Porto, Rome) this number is expected to double within the next one or 2 years. Conclusions: A European registry for all patients with lipodystrophy will provide a platform for improved research in the area of lipodystrophy. All physicians from Europe and neighbouring countries caring for patients with lipodystrophy are invited to participate in the ECLip Registry. Study registration: ClinicalTrials.gov (NCT03553420). Registered 14 March 2018, retrospectively registered
Expanding the <em>HPSE2</em> Genotypic Spectrum in Urofacial Syndrome, A Disease Featuring a Peripheral Neuropathy of the Urinary Bladder
Copyright \ua9 2022 Beaman, Lopes, Hofmann, Roesch, Promm, Bijlsma, Patel, Akinci, Burgu, Knijnenburg, Ho, Aufschlaeger, Dathe, Voelckel, Cohen, Yue, Stuart, Mckenzie, Elvin, Roberts, Woolf and Newman. Urofacial (also called Ochoa) syndrome (UFS) is an autosomal recessive congenital disorder of the urinary bladder featuring voiding dysfunction and a grimace upon smiling. Biallelic variants in HPSE2, coding for the secreted protein heparanase-2, are described in around half of families genetically studied. Hpse2 mutant mice have aberrant bladder nerves. We sought to expand the genotypic spectrum of UFS and make insights into its pathobiology. Sanger sequencing, next generation sequencing and microarray analysis were performed in four previously unreported families with urinary tract disease and grimacing. In one, the proband had kidney failure and was homozygous for the previously described pathogenic variant c.429T>A, p.(Tyr143*). Three other families each carried a different novel HPSE2 variant. One had homozygous triplication of exons 8 and 9; another had homozygous deletion of exon 4; and another carried a novel c.419C>G variant encoding the missense p.Pro140Arg in trans with c.1099-1G>A, a previously reported pathogenic splice variant. Expressing the missense heparanase-2 variant in vitro showed that it was secreted as normal, suggesting that 140Arg has aberrant functionality after secretion. Bladder autonomic neurons emanate from pelvic ganglia where resident neural cell bodies derive from migrating neural crest cells. We demonstrated that, in normal human embryos, neuronal precursors near the developing hindgut and lower urinary tract were positive for both heparanase-2 and leucine rich repeats and immunoglobulin like domains 2 (LRIG2). Indeed, biallelic variants of LRIG2 have been implicated in rare UFS families. The study expands the genotypic spectrum in HPSE2 in UFS and supports a developmental neuronal pathobiology
Seismological constraints for the dyke emplacement of the July-August 2001 lateral eruption at Mt. Etna volcano, Italy
In this paper we report seismological evidence regarding the emplacement of the dike that fed the July 18 - August
9, 2001 lateral eruption at Mt. Etna volcano. The shallow intrusion and the opening of the eruptive fracture
system, which mostly occurred during July 12, and July 18, were accompanied by one of the most intense seismic
swarms of the last 20 years. A total of 2694 earthquakes (1 ÂŁ Md ÂŁ 3.9) were recorded from the beginning of the
swarm (July 12) to the end of the eruption (August 9). Seismicity shows the upward migration of the dike from
the basement to the relatively thin volcanic pile. A clear hypocentral migration was observed, well constraining
the upwards propagation of a near-vertical dike, oriented roughly N-S, and located a few kilometers south of the
summit region. Earthquake distribution and orientation of the P-axes from focal mechanisms indicate that the
swarm was caused by the local stress source related to the dike intrusion
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