Search results for "modelling"

Obésité et grossesse : étude de l'influence d'un marqueur de l'obésité sur les mécanismes cellulaires et tissulaires de l'accouchement dans un modèle…

2012

Maternal obesity is associated with a wide spectrum of delivery disorders, such as delayed or post-term delivery, that might be explained partly by the increase in plasma leptin levels in obese women, as leptin inhibits in vitro myometrial contractility. Delivery involves uterine apoptosis and remodelling of the extracellular matrix, via the activation of matrix metalloproteinases (MMP). This study was aimed to assess the role of leptin on human myometrium, by studying the interaction of leptin with lipopolysaccharide (LPS)-induced apoptosis and degradation of myometrial collagen.Myometrial biopsies were obtained from women undergoing caesarean delivery before labour onset. The effects of l…

Particle transport in recirculated liquid metal flows

2008

PurposeAims to present recent activities in numerical modeling of turbulent transport processes in induction crucible furnace.Design/methodology/approach3D large eddy simulation (LES) method was applied for fluid flow modeling in a cylindrical container and transport of 30,000 particles was investigated with Lagrangian approach.FindingsParticle accumulation near the side crucible boundary is determined mainly by the ρp/ρ ratio and according to the presented results. Particle settling velocity is of the same order as characteristic melt flow velocity. Particle concentration homogenization time depends on the internal flow regime. Separate particle tracks introduce very intensive mass exchang…

Numerical and experimental study of liquid metal stirring by rotating permanent magnets

2018

In this work, we study liquid gallium stirring by rotating permanent magnets. We demonstrate possibility of easily creating different flow patterns by rotating permanent magnets, which can be industrially important for controlling heat and mass transfer processes in the system. Unlike the typical approach of simulating magnet rotation as a transient problem and time-averaging the Lorentz forces, we solve the magnet rotation as a harmonic (frequency domain) problem, which leads to forces equal to time-averaged ones and decreases the simulation time considerably. Numerical results are validated using qualitative flow structure results from the neutron radiography visualization of tracer parti…

Tectonique et architecture des bassins intracratoniques Paléozoïques : impact sur l’enregistrement sédimentaire et la géométrie des réservoirs associ…

2019

The Paleozoic Saharan platform including the peri-Hoggar Basins (i.e. Murzuq, Illizi, Mouydir, Ahnet, Reggane and Tim Mersoï basins) are defined as intracraonic basins. Their histories have been dominated by slow long-wavelength vertical motions leading to overall low subsidence rate (i.e ca. 10 m/Ma to 50 m/Ma) and accumulation of an extensive cover of platformal sediments (i.e. shallow deposits environments), rhythmed by pulsatile periods of increasing and decreasing rate probably triggered by regional geodynamic events. The vertical motions of the platform produced several arches also called domes, swells, highs, ridges (e.g. the Tihemboka, Amguid El Biod, Arak-Foum Belrem and Azzel Matt…

Plasma Pro-C3 (N-terminal type III collagen propeptide) predicts fibrosis progression in patients with chronic hepatitis C.

2014

BACKGROUND & AIMS: Fibrogenesis results in release of certain extracellular matrix protein fragments into the circulation. We evaluated the diagnostic and prognostic performance of two novel serological markers, the precisely cleaved N-terminal propeptide of type III collagen (Pro-C3) and a peptide of helical collagen type III degradation (C3M), in chronic hepatitis C (CHC) patients. METHOD: Pro-C3 and C3M were measured by ELISA in plasma from CHC patients (n = 194) from a prior phase II antifibrotic trial (NCT00244751). Plasma samples and paired liver biopsies were obtained at baseline and after 1-year. Patients were stratified according to Ishak stages 2-4. Internal cross-validation w…

Physico-chemical evolution of low-pH cements : influence of the temperature and the retention mechanisme of alkalins

2010

Because of their high alkalinity, Portland cement (OPC)-based materials may have deleterious effects in an underground waste repository. A solution would be to use low-alkalinity cements (also referred as low-pH cements) generating interstitial solutions with a reduced pH (11 instead of 13.5 for OPC), and thus showing an improved chemical compatibility with the repository environment. In this work, the investigated formulations were based on binary (OPC / silica fume) or ternary (OPC / silica fume / slag or fly ash) blends, with high substitution levels of CEM I (from 30% to 80%). This research project met two main objectives: (i) study the chemical evolution of low-pH cements at 50°C or 80…

Perceived Value in Tourism: A PLSPM Approach

2015

This paper examines the concept of perceived value in rural tourism referred to the specific context of Sicilian holiday farms. Herein main dimensions composing the rural tourist perceived value (RTPV) are discussed. Using Partial Least Squares Path Modelling (PLSPM) –a statistical technique especially suitable for exploratory purposes with small samples – a theoretical structural model of the multidimensional structure of RTPV is tested and the causal relationships among RTPV and its dimensions (Functional, Convenience, Emotional and Educational) and among RTPV and tourists’ satisfaction and loyalty are explored. Results from a field survey on 350 tourists give a contribution in terms of i…

How upper secondary students solve algebraic word problems in the area of mathematical modelling : A case study of one group of Norwegian students

2019

Masteroppgave matematikkdidaktikk MA500 - Universitetet i Agder 2019 For å imøtekomme nye utfordringer på skolen, i jobb og i livet, kan elever ha behov for åtilpasse og utvide den matematikken de kan. Dette krever at elever evner, i noen grad, åsette skolematematikken i forbindelse med hverdagslige kontekster og motsatt. Matema-tisk modellering er en av de hensiktsmessige mediene for å støtte sammenhengen mellomskolematematikken og virkeligheten. Forskning har vist at det er en sterk tilbøyelighet ipensumet mot matematisk modellering og at i stedet høynivå matematikk er ansett somviktig, mest på videregående nivå. Igjen, forskning viser at elever har større utfordringermed abstrakte (fakta…

Statistical models and inference for spatial point patterns with intensity-dependent marks

2009

Molecular Modelling on Leptin and the Ob Receptor as anti-obesity target

2012

Obesity is a chronic pathology with multi-factorial aetiology, characterized by extreme body weight due to storing of fat in the adipose tissue, caused by an increase of caloric income, decrease of energetic intake, or both. The body weight control is a mechanism finely regulated by several hormonal, metabolic, and nervous pathways. Recessive homozygous mutations in the ob/ob and db/db mouse strain cause extreme obesity. The products of the ob and db genes are leptin and its receptor, respectively (1,2). The leptin receptor is critical for energy homeostasis and regulation of food uptake. Leptin is a 16 kDa hormone that is mainly secreted by fat cells into the bloodstream. Under normal circ…