Search results for "Transient"

Bounds on transient phase plastic deformations in optimal design of steel frames subjected to cyclic loads

2009

A minimum volume multicriterion design of elastic perfectly plastic steel frames subjected to a combination of quasi-static fixed and cyclic loads, bounding the transient phase plastic deformations, is proposed. The problem is formulated according to a plastic shakedown criterion, so that incremental and instantaneous collapse are certainly prevented when the frame is subjected to very strongly amplified cyclic loads. The further condition that the structure must also behave elastically in serviceability conditions is imposed. Since the steady-state loading history is known it is possible to directly bound the steady-state plastic deformations. By applying a suitable own bounding theorem, i…

Biophysical Characterization of TRPV2 Ion Channel

2012

TRPV2 is a member of the superfamily of the Transient Receptor Potential (TRP) ion channels. These channels are assembled into homotetramers and allow cations across the membrane in response to physico-chemical stimuli such as heat, pressure, osmotic changes, etc. TRPV2 is an orphan receptor, since no specific endogenous ligand has been identified yet. To better understand the role of TRPV2 and to go further into its function, sequence analysis of orthologs for TRPV2 has been performed in order to define common and differential architectural regions. Preliminary biophysical characterization such as thermal stability, and secondary structure composition analysis has been carried out on the d…

Storm sewer pressurization transient – an experimental investigation

2014

Pipe pressurization is examined experimentally by 144 laboratory experiments in a circular tilting pipe between two tanks, in which the transient was triggered by sudden closing of the downstream tank outlet. The experiments cover ranges of values of slope, velocity and filling ratio of the open-channel flow not explored in previous studies. Situations involving considerable air quantity and consequent intense pressure oscillations were also reproduced. Two different pressurization patterns, defined as “smooth” and “abrupt”, were observed, but only the abrupt pattern produced intense pressure oscillations. The comparison among all the abrupt pressurization surges showed how the oscillations…

Smoothed Particle ElectroMagnetics: A mesh-free solver for transients

2006

AbstractIn this paper an advanced mesh-free particle method for electromagnetic transient analysis, is presented. The aim is to obtain efficient simulations by avoiding the use of a mesh such as in the most popular grid-based numerical methods. The basic idea is to obtain numerical solutions for partial differential equations describing the electromagnetic problem by using a set of particles arbitrarily placed in the problem domain. The mesh-free smoothed particle hydrodynamics method has been adopted to obtain numerical solution of time domain Maxwell's curl equations. An explicit finite difference scheme has been employed for time integration. Details about the numerical treatment of elec…

Fluid dynamics with saturated minijet initial conditions in ultrarelativistic heavy-ion collisions

2014

Using next-to-leading order perturbative QCD and a conjecture of saturation to suppress the production of low-energy partons, we calculate the initial energy densities and formation times for the dissipative fluid dynamical evolution of the quark-gluon plasma produced in ultrarelativistic heavy-ion collisions. We identify the framework uncertainties and demonstrate the predictive power of the approach by a good global agreement with the measured centrality dependence of charged particle multiplicities, transverse momentum spectra and elliptic flow simultaneously for the Pb+Pb collisions at the LHC and Au+Au at RHIC. In particular, the shear viscosity in the different phases of QCD matter is…

Transient elastography (TE) as a tool to evaluate acute liver damage: A prospective, multicentric cohort study

2008

Fibrospleen: Measuring spleen stiffness by transient elastography increases accuracy of staging of liver fibrosis and of portal hypertension in chron…

2009

Reliability of liver stiffness measurement in non-alcoholic fatty liver disease: the effects of body mass index

2011

Summary Background  Liver stiffness measurement (LSM) using transient elastography (TE) is used to stage fibrosis in patients with liver disease, diagnostic reliability and the factors affecting its performance in patients with non-alcoholic fatty liver disease (NAFLD) are incompletely understood. Aim  To assess LSM. Methods  Consecutive NAFLD patients (n = 169), assessed by liver biopsy (Kleiner score), anthropometrical, biochemical and metabolic features, underwent LSM using TE with standard M probe. Results  Liver stiffness measurement was not reliable in 23 patients (14%) due to obesity. Among patients with a reliable TE, a LSM value >7.25 kPa was the best cut-off for predicting signifi…

Liver stiffness measurement by transient elastography predicts early recovery from acute hepatitis

2010

We read with interest the lead article by Castera and Pinzani,1 particularly the comment regarding the role of transient elastography (TE) in the context of acute hepatitis (AH). The assumption that liver stiffness is determined exclusively by hepatic fibrosis has been challenged by evidence that patients with AH can have high values of liver stiffness measurement (LSM) by TE.2 AH is a suitable model for studying the kinetics of LSM, since inflammation and necrosis increase rapidly and sometimes massively, but may revert with equal speed. We evaluated 92 consecutive patients (mean age 41.8±16.3 years, 71.7% males) with symptomatic AH to assess how LSM was influenced by aetiology, and whethe…

Comparison of Histochemical Staining Methods and Correlation with Transient Elastography in Acute Hepatitis.

2014

<b><i>Objective:</i></b> To compare Masson's trichrome (MT), Sirius red (SR) and orcein staining in acute hepatitis (AH) and to correlate them with<b> </b>transient elastography (TE),<b> </b>a noninvasive method to assess hepatic fibrosis. <b><i>Methods:</i></b> We evaluated liver stiffness by TE in a cohort of 34 consecutive patients and assessed MT-, SR- and orcein-stained biopsies using the METAVIR scoring system and digital image analysis (DIA). <b><i>Results:</i></b> MT and SR both showed severe fibrosis (stage III-IV, DIA = 12.7%). Orcein showed absent or mild fibrosis (stage 0-II, DIA = 4.…