Search results for "Transient"

Modeling of Melt Flow and Heat Transfer in Stationary Gas Tungsten Arc Welding with Vertical and Tilted Torches

2021

A 3D numerical simulation was conducted to study the transient development of temperature distribution in stationary gas tungsten arc welding with filler wire. Heat transfer to the filler wire and the workpiece was investigated with vertical (90°) and titled (70°) torches. Heat flux, current flux, and gas drag force were calculated from the steady-state simulation of the arc. The temperature in the filler wire was determined at three different time intervals: 0.12 s, 0.24 s, and 0.36 s. The filler wire was assumed not to deform during this short time, and was therefore simulated as solid. The temperature in the workpiece was calculated at the same intervals using heat flux, current flux, ga…

The transient gravitational-wave sky

2013

Interferometric detectors will very soon give us an unprecedented view of the gravitational-wave sky, and in particular of the explosive and transient Universe. Now is the time to challenge our theoretical understanding of short-duration gravitational-wave signatures from cataclysmic events, their connection to more traditional electromagnetic and particle astrophysics, and the data analysis techniques that will make the observations a reality. This paper summarizes the state of the art, future science opportunities, and current challenges in understanding gravitational-wave transients.

Experimental and Numerical Validation of a Wind Gust Facility

2013

The study of a vehicle moving through a lateral wind gust has always been a difficult task due to the difficulties in granting the right similitude. The facility proposed by Ryan and Dominy has been one of the best options to carry it out. In this approach, a double wind tunnel is used to send a lateral moving gust on a stationary model. Using this idea as a starting point, the ISAE has built a dedicated test bench for lateral wind studies on transient conditions. Experimental work has been carried out by means of time-resolved PIV, aiming at studying the unsteady interpenetration of the two flows coming from each wind tunnel. Meanwhile, a 3D CFD model based on URANS was set up, faithfully …

Transient Optical Absorption and Luminescence in Calcium Tungstate Crystal

2001

Timing techniques applied to distributed modular high-energy astronomy: the H.E.R.M.E.S. project

2021

The HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites -- Technologic and Scientific Pathfinder) is an in-orbit demonstration of the so-called distributed astronomy concept. Conceived as a mini-constellation of six 3U nano-satellites hosting a new miniaturized detector, HERMES-TP/SP aims at the detection and accurate localisation of bright high-energy transients such as Gamma-Ray Bursts. The large energy band, the excellent temporal resolution and the wide field of view that characterize the detectors of the constellation represent the key features for the next generation high-energy all-sky monitor with good localisation capabilities that will play a pivotal role in the future …

Safety and Pharmacokinetics of Glecaprevir/Pibrentasvir in Adults With Chronic Genotype 1–6 Hepatitis C Virus Infections and Compensated Liver Disease

2019

Background: Untreated, chronic hepatitis C virus (HCV) infection may lead to progressive liver damage, which can be mitigated by successful treatment. This integrated analysis reports the safety, efficacy, and pharmacokinetics (PK) of the ribavirin-free, direct-acting, antiviral, fixed-dose combination of glecaprevir/pibrentasvir (G/P) in patients with chronic HCV genotype 1-6 infections and compensated liver disease, including patients with chronic kidney disease stages 4 or 5 (CKD 4/5). Methods: Data from 9 Phase II and III clinical trials, assessing the efficacy and safety of G/P treatment for 8-16 weeks, were included. The presence of cirrhosis was determined at screening using a liver …

Computational annotation of genes differentially expressed along olive fruit development

2009

Abstract Background Olea europaea L. is a traditional tree crop of the Mediterranean basin with a worldwide economical high impact. Differently from other fruit tree species, little is known about the physiological and molecular basis of the olive fruit development and a few sequences of genes and gene products are available for olive in public databases. This study deals with the identification of large sets of differentially expressed genes in developing olive fruits and the subsequent computational annotation by means of different software. Results mRNA from fruits of the cv. Leccino sampled at three different stages [i.e., initial fruit set (stage 1), completed pit hardening (stage 2) a…

Negative U‐properties of the oxygen‐vacancy in ZnO

2006

It is shown that the intensity of the oxygen vacancy (VO) related emission in ZnO at 2.45 eV correlates to the concentration of the donor level E4. E4 is located 530 meV below the conduction band and attributed to the VO0/++ recharging. Deep level transient spectroscopy (DLTS) experiments with optical excitation locate the VO2+/+ level position 140 meV below the conduction band and give evidence for the “negative- U” properties of the oxygen vacancies in ZnO. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Photochemical-chemiliminometric determination of aldicarb in a fully automated multicommutation based flow-assembly

2004

[EN] A sensitive and fully automated method for determination of aldicarb in technical formulations (Temik) and mineral waters is proposed. The automation of the flow-assembly is based on the multicommutation approach, which uses a set of solenoid valves acting as independent switchers. The operating cycle for obtaining a typical analytical transient signal can be easily programmed by means of a home-made software running in the Windows environment. The manifold is provided with a photoreactor consisting of a 150 cm long x 0.8 mm i.d. piece of PTFE tubing coiled around a 20 W low-pressure mercury lamp. The determination of aldicarb is performed on the basis of the iron(III) catalytic minera…

Factors associated with early recurrence at the first evaluation of patients with transient ischemic attack.

2014

Abstract We aimed to identify factors easily collected at admission in patients with transient ischemic attack (TIA) that were associated with early recurrence, so as to guide clinicians’ decision-making about hospitalization in routine practice. From September 2011 to January 2013, all TIA patients who were referred to the University Hospital of Dijon, France, were identified. Vascular risk factors and clinical information were collected. The etiology of the TIA was defined according to the results of complementary examinations performed at admission as follows: large artery atherosclerosis (LAA-TIA) TIA, TIA due to atrial fibrillation (AF-TIA), other causes, and undetermined TIA. Logistic…