This paper presents a dynamic optimization procedure of grade changes of polyethylene production. The optimization is built upon a novel modular Modelica library containing e.g., non-linear DAE models for polyethylene reactors based on models currently used in nonlinear MPC of industrial reactors at Borealis AB. Using Optimica, which extends the Modelica language with constructs for optimization p

An experimental characterization of friction forces between asymmetric surfaces in the micro-regime is presented. The lateral motion and force-measurement capability of an instrumented indenter (triboindenter) is characterized and explored for determining friction properties at low velocities. Friction experiments are performed using the triboindenter with high repeatability. It is observed that r

This paper presents a systematic approach to robust preconditioning for gradient based non-linear inverse scattering algorithms. In particular, one- and two-dimensional inverse problems are considered where the permittivity and conductivity profiles are unknown and the input data consists of the scattered field over a certain bandwidth. A time-domain least-squares formulation is employed and the i

An improved design for acoustic particle separation in multichannel chips is presented. By wavelength matching of the microfluidic channel widths and the width of the interlacing bulk silicon, a well tuned resonating multilayer system can be accomplished. The acoustically tuned microchip offers considerable improvements in regards to particle focusing performance, i.e. separation efficiency, at fi

In an attempt to shed light on the role of the polyamines, putrescine, spermidine, and spermine in cell cycle progression, polyamine biosynthesis has been analyzed during the cell cycle of Chinese hamster ovary cells, and cell cycle kinetics have been investigated in cells treated with polyamine biosynthesis inhibitors. Cells were synchronized with the mitotic detachment technique, and at various

Extended producer responsibility (EPR) is a concept from Industrial Ecology that has changed waste management policies inside and gradually outside the member countries of the Organisation for Economic Co-operation and Development (OECD). This article bridges the gap in our understanding of the policy process wherein policy change occurred. It employs the Advocacy Coalition Framework (ACF) to expl

Shopping has since long been recognized as a possible source of enjoyment. It has been argued that consumers of today devote ever more of their spare time to shopping. Within the domain of marketing, scholars have been successful in outlining consumers' motives for engaging in shopping as a leisure-time enjoyment. Minor attention has however been devoted to explorations of how or why such shopping

This paper discusses control of dissolved oxygen in a bioreactor when the stirrer speed is used as control signal. During batch and fed-batch cultivations the operating conditions change significantly which causes tuning problems, especially when performance requirements are high. A linearized process model reveals that the variations in the oxygen dynamics are mainly due to changes in the volumet

Computer control is entering all facets of life from home electronics to production of different products and material. Many of the computers are embedded and thus ``hidden'' for the user. In many situations it is not necessary to know anything about computer control or real-time systems to implement a simple controller. There are, however, many situations where the result will be much better when

In this project, we have explored RuO2 and Ru nanoparticles (∼ ∼10 and ∼ ∼5 nm, respectively, estimated from XRD data) to be used as gate material in field effect sensor devices. The particles were synthesized by wet chemical procedure. The capacitance versus voltage characteristics of the studied capacitance shifts to a lower voltage while exposed to reducing gases. The main objectives are to imp