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Selected AbstractsMechanical and fracture properties for predicting cracking in semi-sweet biscuitsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2005Qasim Saleem Summary Mechanical and fracture properties required for predicting crack development in semi-sweet (,rich tea') biscuits have been experimentally determined. Pilot-scale biscuits of different fat concentrations were prepared and studied with commercial biscuits at different moisture contents. Bending modulus, fracture stress and strain were measured using three-point bending tests. All biscuit types showed considerable dependence on moisture content over a range of 4,12%. Young's modulus and failure stress showed a uniform decrease and failure strain showed an increase with increasing moisture content. For pilot-scale biscuits of different fat concentrations, an increase in fat level caused a decrease in modulus and failure stress values; however, the failure strains were very similar for all the fat types. The testing of the samples with top surface up and top surface down revealed that the sample orientation does not affect the measured parameters. The measured parameters also did not show any directional dependence within the plane, thus assuring that the assumption of an isotropic material would be valid for modelling. The mechanical and fracture properties measured in this study will serve as a very useful set of data to predict the stress state and cracking of the checked biscuits. [source] Predicting the effects of perturbations on ecological communities: what can qualitative models offer?JOURNAL OF ANIMAL ECOLOGY, Issue 5 2005DAVE RAMSEY Summary 1Quantitative predictions of the effects of perturbations on communities of interacting species have often proved to be difficult. However, if precise predictions are not a requirement then qualitative models of community dynamics offer an alternative method for predicting species responses to perturbations. 2We used two qualitative modelling approaches to predict the effects of predator control on the fledging rate of an endangered New Zealand bird, the North Island kokako. The first approach was based on loop analysis and provided predictions on the probable direction of change in species abundances to single species perturbations. The second approach, ,fuzzy interaction webs', used fuzzy logic in the framework of a fuzzy cognitive map to provide predictions on the probable magnitude of change in species abundances to perturbations. 3Using both methods, we predicted the qualitative change in the equilibrium fledging rates of kokako under various regimes of single- and multispecies predator control (ship rats, brushtail possums and stoats). Single species control was insufficient to lift the fledging rate from ,low' to ,moderate'. However, simultaneous control of both ship rats and possums had the greatest influence on the fledging rates compared with any other combination as a result of the additional indirect effect of ship rat control on stoat abundance. 4We propose qualitative modelling of community dynamics as a method suitable for predicting the effects of perturbations in complex ecological communities that can encapsulate diverse sources of knowledge about food web interactions. We believe that these methods are a useful set of heuristic tools that can be used to propose testable hypotheses about ecosystem functioning that can complement existing statistical and quantitative modelling approaches. [source] A physical organic mechanistic approach to understanding the complex reaction network of hemostasis (blood clotting)JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 10 2007Christian J. Kastrup Abstract This review focuses on how the mechanistic approach of physical organic chemistry can be used to elucidate the mechanisms behind complex biochemical networks. The dynamics of biochemical reaction networks is difficult to describe by considering their individual reactions, just as the dynamics of organic reactions is difficult to describe by considering individual electrons and atomic nuclei. Physical organic chemists have developed a useful set of tools to predict the outcome of organic reactions by separating the interacting molecules into modules (functional groups), and defining general rules for how these modules interact (mechanisms). This review shows how these tools of physical organic chemistry may be used to describe reaction networks. In addition, it describes the application of these tools to develop a mechanistic understanding of the dynamics of the complex network of hemostasis, which regulates blood clotting. Copyright © 2007 John Wiley & Sons, Ltd. [source] An assessment strategy for identifying legacy system evolution requirements in eBusiness contextJOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 4-5 2004Lerina Aversano Abstract The enactment of e Business processes requires the effective usage of the existing legacy applications in the e Business initiatives. Technical issues are not enough to drive the evolution of the existing legacy applications, but problems concerning the perspectives, strategies, and business of the enterprises have to be considered. In particular, there is a strict relationship between the evolution of the legacy systems and the evolution of the e Business processes. This paper proposes a strategy to extract the requirements for a legacy system evolution from the requirements of the e Business evolution. The proposed strategy aims at characterizing the software system within the whole environment in which its evolution will be performed. It provides a useful set of attributes addressing technical, process, and organizational issues. Moreover, a set of assessment activities is proposed affecting the order in which the attributes are assessed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Approaches to Evaluate Water Quality Model Parameter Uncertainty for Adaptive TMDL Implementation,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2007Craig A. Stow Abstract:, The National Research Council recommended Adaptive Total Maximum Daily Load implementation with the recognition that the predictive uncertainty of water quality models can be high. Quantifying predictive uncertainty provides important information for model selection and decision-making. We review five methods that have been used with water quality models to evaluate model parameter and predictive uncertainty. These methods (1) Regionalized Sensitivity Analysis, (2) Generalized Likelihood Uncertainty Estimation, (3) Bayesian Monte Carlo, (4) Importance Sampling, and (5) Markov Chain Monte Carlo (MCMC) are based on similar concepts; their development over time was facilitated by the increasing availability of fast, cheap computers. Using a Streeter-Phelps model as an example we show that, applied consistently, these methods give compatible results. Thus, all of these methods can, in principle, provide useful sets of parameter values that can be used to evaluate model predictive uncertainty, though, in practice, some are quickly limited by the "curse of dimensionality" or may have difficulty evaluating irregularly shaped parameter spaces. Adaptive implementation invites model updating, as new data become available reflecting water-body responses to pollutant load reductions, and a Bayesian approach using MCMC is particularly handy for that task. [source] | ||||||||||