Computer-aided Process Modeling Research Articles

Cascades in Compartments: En Route to Machine-Assisted Biotechnology.

Biological compartmentalization is a fundamental principle of life that allows cells to metabolize, propagate, or communicate with their environment. Much research is devoted to understanding this basic principle and to harness biomimetic compartments and catalytic cascades as tools for technological processes. This Review summarizes the current state-of-the-art of these developments, with a special emphasis on length scales, mass transport phenomena, and molecular scaffolding approaches, ranging from small cross-linkers over proteins and nucleic acids to colloids and patterned surfaces. We conclude that the future exploration and exploitation of these complex systems will largely benefit from technical solutions for the integrated, machine-assisted development and maintenance of a next generation of biotechnological processes. These goals should be achievable by implementing microfluidics, robotics, and added manufacturing techniques supplemented by theoretical simulations as well as computer-aided process modeling based on big data obtained from multiscale experimental analyses.

Computer-aided process modeling with ModKit

Tight time and cost constraints force chemical process industries to continuously reduce their experimental effort during chemical process development and to facilitate the application of model-based process technology. Nevertheless, the effort of setting up a detailed mathematical model for a chemical process remains still high due to the large variety of chemical process units and physical phenomena as well as increasing requirements on the sophistication of models. To overcome this modeling bottleneck considerable effort has to be spent with the systematization of process models, the formalization of their representation, and the development of knowledge-based software tools. This contribution deals with the modeling environment ModKit, which supports the systematic development, maintenance, and reuse of chemical process models. It will be shown, how informal textual or graphical information defining requirements on models can be specified by use of ModKit. Furthermore, computer-aided means for the structural and behavioural description of chemical processes, as well as an approach for the support of the workflow of model development will be described.

Communication: computer aided engineering in the next millennium

The next generation of computer aided tools should address the traditional role of engineering within a manufacturing organization, i.e. accurate communication of manufacturing specifications. Communication is the business of manufacturing engineering: translating design specifications into process plans and information such as estimating time and cost, process geometry creation and tolerance charting, determining tooling, and the recording of best practices. The integration of the product and process geometry with manufacturing knowledge is evolving through the use of computer aided process modeling and best practice sharing, to better serve production, which in turn delivers quality product at the right cost and tempo. These computer aided systems will have easy accessibility, inherent configuration control, and a “manufacturing language.”

Trends in computer-aided process modeling

Process modeling is an important task during many process engineering activities such as steady-state and dynamic process simulation, process synthesis or control system design and implementation. The demand for models of varying detail is expected to steadily increase in the future due to advances in model-based process engineering methodologies. Computer assistance to support the development and implementation of adequate and transparent models is indispensable to minimize the engineering effort. The state of the art and current trends in computer-aided modeling are presented in this contribution which is intended to serve as a survey and a tutorial at the same time.

A program for handling multiple phases of the design cycle in process control system design

An architecture for a Computer Aided Process Modelling and Control System Design program is proposed. The program is designed to enable process-control engineers to tackle various phases of the overall process modelling and control system design cycle. Techniques used include cause-effect and structural controllability analyses, qualitative and bond graph modelling, numerical simulation, computer guided specification and control system design. Early implementation results are presented.

Effect of Process Variables on Die-Billet Temperature History in a Slow Speed Hot Coining Type Process

A computer code is developed as a part of an ongoing project on computer aided process modelling of forging operation, to simulate heat transfer in a die-billet system. The code developed on a stage-by-stage technique is based on an Alternating Direction Implicit scheme. The experimentally validated code is used to study the effect of process specifics such as preheat die temperature, machine ascent time, rate of deformation, and dwell time on the thermal characteristics in a batch coining operation where deformation is restricted to surface level only.

Status report on X-ray lithography

The need to use X-ray lithography for the large-scale manufacture of future generations of integrated circuits is discussed and an overview of world efforts to develop the necessary technologies is presented. The emphasis is on synchrotron radiation from electron storage rings as the light source. The work of the Wisconsin Center for X-Ray Lithography at the University of Wisconsin Synchrotron Radiation Center is discussed, including recent results in the areas of exposure stations, X-ray resists, masks and computer-aided process modeling.

Electronic Manufacturing Process Systems Cost Modeling and Simulation Tools

Recent National Science Foundation [1] and National Research Council [2] studies have discussed electronics industry needs in the areas of computer-aided process modeling and simulation tools to support the Computer Integrated Manufacturing (CIM) electronics-design-for-manufacturing process. In this paper, we present a summary of pioneering efforts in the modeling and simulation areas by Northern Telecom Ltd. (NTL) to support a technology/product leadership-setting-position with Companion Haudsfree Speakerphone, Electronic Telephone, Office products. The simple software tools to be discussed will cover printed wiring board assembly (PWBA) technology cost modeling, tolerance analysis and yield prediction including experiment design, impact of function complexity on optimum module size and component density, component sample plans and statistics and optimum component value selections. These tools are applicable to programmable calculators and PC's.

Computer-Aided Process Modelling of Hot Forging and Extrusion of Aluminum Alloys

Research on process modeling of hot forging and extrusion of aircraft structural parts has been conducted and powerful and efficient software developed for the analysis of metal flow during forging of complex shapes using the rigid-plastic and rigid-viscoplastic finite-element method. New constitutive equations and flow rules have been developed for fully dense as well as partially dense P/M material and this information integrated into the analysis software through a material data base. A new concept for the design of streamlined dies of arbitrary shape has been developed and used in the manufacture of dies for the extrusion of a complex structure from a newly developed SiC composite aluminum alloy. Visualization and understanding of the complex three-dimensional geometry are enhanced by the use of shaded color graphics.