Hint: An educational software for heat exchanger network design with the pinch method

A free piece of educational software for heat exchanger network design based on the pinch method is presented. The interface of the program has been designed focusing on getting a clear presentation of the concepts of the pinch design methods and letting students the control of all the stages of the design. The program guides students through all the main steps of the design, including energy and cost targeting, utilities selection, heat exchanger network specification, and optimisation and retrofitting analysis. The program has been tested in a MSc pinch technology course for several years, and the feedback obtained from students during this period has been used to optimise the program functionality and its interface. The use of the program improves the efficiency of the course since it let students practice the concepts of the pinch method while relieving them of tedious repetitive calculations.     

重要应用化学软件和数据库导论

重点介绍著名免费应用化学专业软件和数据库的主要功能和使用方法。简介一些重要商业版应用化学专业软件的特点。通过本文可以看到现代应用化学专业软件的最新发展动态和水准。     

Evaluating variability and uncertainty separately in microbial quantitative risk assessment using two R packages

Quantitative risk assessment has emerged as a valuable tool to enhance the scientific basis of regulatory decisions in the food safety domain. This article introduces the use of two new computing resources (R packages) specifically developed to help risk assessors in their projects. The first package, “fitdistrplus”, gathers tools for choosing and fitting a parametric univariate distribution to a given dataset. The data may be continuous or discrete. Continuous data may be right-, left- or interval-censored as is frequently obtained with analytical methods, with the possibility of various censoring thresholds within the dataset. Bootstrap procedures then allow the assessor to evaluate and model the uncertainty around the parameters and to transfer this information into a quantitative risk assessment model. The second package, “mc2d”, helps to build and study two dimensional (or second-order) Monte-Carlo simulations in which the estimation of variability and uncertainty in the risk estimates is separated. This package easily allows the transfer of separated variability and uncertainty along a chain of conditional mathematical and probabilistic models. The usefulness of these packages is illustrated through a risk assessment of hemolytic and uremic syndrome in children linked to the presence of Escherichia coli O157:H7 in ground beef. These R packages are freely available at the Comprehensive R Archive Network (cran.r-project.org).     

An Art of Connectivity

Do building information modelling (BIM) systems sufficiently cater for the subtleties of the architect's role? Tristan Gobin, Sebastian Andraos and Thibault Schwartz of London-based robot control specialists HAL Robotics think not. They advocate the development of systems that offer more levels of abstraction, allowing architects, engineers and others who are not necessarily familiar with source code to assist in the elaboration of platform languages. Only then will they become true tools for creativity that reinforce continuity between the various actors involved in building design and construction.