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Modeling Software (modeling + software)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Pilot-scale combustion of fast-pyrolysis bio-oil: Ash deposition and gaseous emissions

ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2009
Ala Khodier
Abstract Fast pyrolysis is a promising method to transform solid biomass into a liquid product called "bio-oil" with an energy density of four to five times greater than the feedstock. The process involves rapidly heating biomass to 450,600°C in the absence of air and condensing the vapor produced to give bio-oil. Typically, 50,75% (weight) of the feedstock is converted into bio-oil that has a number of uses, for example energy production or bio-refinery feedstock. This study investigated the gaseous emissions and ash deposition characteristics resulting from bio-oil combustion in a pilot scale combustion test rig at Cranfield University. A feeding system with heated lines and heated/stirred reservoir was used to feed a spray nozzle in the combustion chamber. Ash deposit samples were collected from the resulting flue gas using three air-cooled probes that simulate heat exchanger tubes with surface temperatures of 500, 600, and 700°C. The deposits formed were analyzed using SEM/EDX and XRD techniques to assess the corrosion potential of the deposits. The results are compared to measured ash deposit compositions formed from biomass combustion. Thermodynamic modeling software was used to make predictions for the partitioning of a range of elements for bio-oil combustion and the results compared to the measured data. © 2009 American Institute of Chemical Engineers Environ Prog, 2009 [source]

Predictive model for the outcome of infliximab therapy in Crohn's disease based on apoptotic pharmacogenetic index and clinical predictors

INFLAMMATORY BOWEL DISEASES, Issue 4 2007
Tibor Hlavaty
Abstract Background: Infliximab (IFX) is an effective therapy for refractory luminal and fistulizing Crohn's disease (CD). Predictors of response could improve selection of patients with a higher probability of favorable outcomes and could improve the safety profile. We aimed to develop a predictive model for the response to infliximab in CD. Methods: Genetic and clinical data collected in a previous pharmacogenetic study of apoptosis genes were analyzed using SAS Enterprise miner modeling software and SPSS 12.0. We proposed a novel apoptotic pharmacogenetic index (API) with a score ranging from 0 (low apoptotic response) to 3 (high apoptotic response) and subsequently developed a decision tree model. Results: Response and remission rates significantly increased with API score (P = 0.005 in the group of patients with luminal CD, P = 0.02 in the group of patients with fistulizing CD). Patients with an API , 1 (n = 59) had the lowest response and remission rates in both the luminal CD (50% and 39.5%, respectively) and fistulizing CD (61.9% and 28.6%, respectively) groups, compared to those with an API of 2 (n = 158), whose response and remission rates were 73.8% and 56.1%, respectively, in the luminal CD group and 85.7% and 44.9%, respectively, in the fistulizing CD group; and those with an API of 3 (n = 10), whose response and remission rates were 100% and 85.7%, respectively, in the luminal CD group and 100% and 0% in the fistulizing CD group. Response in patients with an API , 1 was significantly influenced by concurrent azathioprine therapy in the luminal CD (21.4% versus 78.9%, P < 0.001) and in the fistulizing CD (46.6% versus 100%, P = 0.04) groups. In patients with an API of 2, we saw an interaction with age older than 40 years and location of disease (response 52.2% versus 83.9%, P = 0.008) in the luminal CD group and with baseline CRP greater than 5 mg/L (73.9% versus 93.9%, P = 0.04) in the fistulizing CD group. Conclusions: From our newly proposed apoptotic pharmacogenetic index and clinical predictors, we developed a model for prediction of low, medium, and high responses to the first infusion of IFX in patients with CD. Further studies are needed to confirm the hypothesis generated by our study. (Inflamm Bowel Dis 2007) [source]

Mercury Porosimetry: A General (Practical) Overview

PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 1 2006
Herbert Giesche
Abstract The paper describes general concepts of mercury porosimetry measurements and provides an overview on the current status of pore-network analysis tools. Practical aspects of the technique are described as well as emphasizing the need for testing of model pore structures and the status on pore network modeling software. [source]

A study of residence time distribution in co-rotating twin-screw extruders.

POLYMER ENGINEERING & SCIENCE, Issue 12 2003
Part I: Theoretical modeling
A theoretical model to determine the residence time distribution (RTD) in a co-rotating twin-screw extruder is proposed. The method consists of coupling a continuum mechanics approach with a chemical engineering one and allows us to obtain the RTD without any adjustable parameter. The process parameters are obtained using Ludovic® twin-screw modeling software, and ideal reactors are chosen to depict the screw profile. The influence of screw speed, feed rate and viscosity on RTD are described on a fictive screw profile. The predictions of the model are in qualitative agreement with literature data. The key point of this procedure is obviously the correct association between an ideal reactor and a screw element. [source]