The synthesis of distillation-based separation systems

The last dozen years have produced almost 50 English language articles on the synthesis of separation systems [1]. Most work has considered separating a single relatively ideal mixture into sharply split, usually pure-component products using systems of single-feed, two-product distillation columns. Of late, the work has considered heat-integrating these columns to reduce energy consumption. Present research will very likely produce valuable results for nonsharp separations.Earlier approaches developed both algorithmic- and heuristic-based tree search algorithms for discovering the better systems of non-heat-integrated columns. New results permit the design of heat-integrated systems.The paper highlights the above developments.     

Magneto-sensitive nickel nanowires fabricated by electrodeposition into multi- and single-ion track templates

Polycarbonate templates of (30±1) μm thickness containing cylindrical etched-track nanochannels of (500±50) nm diameter were used for electrodeposition of Ni nanowires. Using 10⁴ channels per cm², the most favourable deposition potential of  − 1.0 V was determined in a potentiostatic mode by varying the deposition potential with respect to an Ag/AgCl reference electrode over a range between  − 0.1 V and  − 1.5 V. The deposition efficiency at  − 1.0 V was estimated around 10%. The resulting single wires had a resistance around 200 Ω and showed an anisotropic magnetoresistance (AMR) effect of 1%, applicable to directionally sensitive magnetic field sensors.     

Increasing the Level of Automation in the Forestry Logging Process with Crane Trajectory Planning and Control

Working with forestry machines requires a great deal of training to be sufficiently skilled to operate forestry cranes. In view of this, it would be desirable within the forestry industry to introduce automated motions, such as those seen in robotic arms, to shorten the training time and make the work of the operator easier. Motivated by this fact, we have developed two experimental platforms for testing control systems and motion‐planning algorithms in real time. They correspond to a laboratory setup and a commercial version of a hydraulic manipulator used in forwarder machines. The aim of this article is to present the results of this development by providing an overview of our trajectory‐planning algorithm and motion‐control method, with a subsequent view of the experimental results. For motion control, we design feedback controllers that are able to track reference trajectories based on sensor measurements. Likewise, we provide arguments to design controllers in an open‐loop for machines that lack sensing devices. Relying on the tracking efficiency of these controllers, we design time‐efficient reference trajectories of motions that correspond to logging tasks. To demonstrate performance, we provide an overview of extensive testing done on these machines.     

Numerical Simulations of Lubricating Grease Flow in a Rectangular Channel with and without Restrictions

This article presents numerical simulations of the laminar flow of lubricating greases in a channel with rectangular cross section. Three greases with different consistencies (NLGI grades 00, 1, and 2) have been considered in three different configurations composed of a rectangular channel without restrictions, one rectangular step restriction, and one double-lip restriction. The driving pressure drop over the channel spans from 30 to 250 kPa. The grease rheology is described by the Herschel-Bulkley rheology model, and both the numerical code and rheology model have been validated with analytical solutions and flow measurements using micro-particle image velocimetry.     

HEAT TRANSFER TO SPHERES FROM A POLYMER MELT

A Galerkin mixed finite-element method was used to predict the effect of fluid elasticity, temperature-dependent fluid properties, shear-dependent fluid properties, and viscous dissipation on the overall rate of heat transfer between a polymer melt and a sphere. A correlation is developed for the Nusselt number that accounts for changes in Péclet number, viscous dissipation, and a temperature-dependent viscosity function     

Decomposition of very large-scale Newton-Raphson based flowsheeting problems

This paper presents an approach for decomposing and solving the very large set of linear equations forming the innermost loop of the Newton-Raphson method. In a straightforward manner the equation set is decomposed into smaller sets, one of each unit in the process and a small set for the overall process. Solution proceeds in three steps: forward elimination for each unit subset, solving completely the residual plus overall process flowsheet equations, and a backward substitution for the unit subsets. The decomposition permits effective use of mass memory when solving very large flowsheeting problems. It also enhances the performance of local pivot strategies used in existing sparse matrix codes.     

Creating Shared Information Spaces to Support Collaborative Design Work

The provision of computer support for collaborative work is a central concern for Information Systems (IS) research and practice. In this paper we present the details of an information flow study undertaken in the household division of a large European design and manufacturing company (Delta). The goal of the study was to elicit user requirements for a computer system to facilitate the collaborative work of new product design teams. These requirements form the basis for the design and development of a Web-based LIRÉ (Living Repository) prototype system, the functionalities, features, and rationale of which are discussed. We also present the results of the evaluation of LIRÉ by the users at Delta and our observations on enhancing the sophistication and usefulness of this class of system. A production version based on the prototype but using commercially available software is currently in use by the New Product Development group at Delta.     

A Model‐Based Approach to Determine the Design Space of Preparative Chromatography

A dream of many pharmaceutical companies is to be able to register a large design space with the regulatory agencies. The problem is that this will require both time and money, so an intelligent method of validating a design space is needed. The design space should only cover operating points at which the process runs optimally. This means that the process should be optimized for different process scenarios and objective functions and the found operating points should be registered as design space. This paper presents a method of determining a good design space by creating Pareto fronts for the ideal case and for various process disturbance scenarios. Optimal operating points are found for varying ratios between feed costs and operating costs, making it possible to make a quantitative choice of an operating point based on this ratio and a qualitative choice based on the whole front. The analysis will show how the chromatographic process can be made more robust when optimizing for higher yields, and how the effect of the critical process parameters can change. To be certain that a robust process is found and that it has a high performance, process disturbances must be taken into account when optimizing a process.     

How to transform local energy systems towards bioenergy? Three strategy models for transformation

During the last decades, the actors within the energy sector in Sweden—as well as in many other countries—have faced increasing demands to transform the energy system towards ecological sustainability. In Sweden these demands have led to numerous policies and economic incentives promoting the use of renewables (which in the Swedish discourse often also includes a connotation of “indigenous energy sources”), and especially the promotion of bioenergy.

To be successful, however, these policies and economic incentives need to be interpreted and adapted to different local contexts and translated into actual transformation processes. In Sweden the municipal authorities have played an important role as interpreters of such institutional frameworks and implementers of local transformation processes. In this article, we re-construct three transformation processes implemented by local municipal authorities, chiselling out the different strategy models developed through them. We argue that such re-constructions help to make visible the different and complex interactions between national institutional frameworks and local contexts as well as interactions within such local contexts. We hope that the strategy models presented can contribute to the understanding of the different kinds of local actions that can foster a further implementation of bioenergy into the energy system.