Ferrogels cross-linked by magnetic particles: Field-driven deformation and elasticity studied using computer simulations

Ferrogels, i.e. swollen polymer networks into which magnetic particles are immersed, can be considered as "smart materials" since their shape and elasticity can be controlled by an external magnetic field. Using molecular dynamics simulations on the coarse-grained level we study a ferrogel in which the magnetic particles act as the cross-linkers of the polymer network. In a homogeneous external magnetic field the direct coupling between the orientation of the magnetic moments and the polymers by means of covalent bonds gives rise to a deformation of the gel, independent of the interparticle dipole-dipole interaction. In this paper we report quantitative measurements of this deformation, the gel's elastic moduli and its magnetic response. Our results demonstrate that these properties depend significantly on the topology of the polymer network

Alternative logistic concepts and their effect within the company and the supply chain

This document presents findings from the simulation of a focused factory at Volvo Aero, Trollhättan. A series of experiments were carried out, aimed at testing a range of alternative logistic concepts. Each concept describes an approach to the control of workflow within the business, for the purpose of determining its effect within the company, and in the wider context of the supply chain

Alternative logistic concepts and their effect within the company and the supply chain

This document presents findings from the simulation of a focused factory at Volvo Aero, Trollhättan. A series of experiments were carried out, aimed at testing a range of alternative logistic concepts. Each concept describes an approach to the control of workflow within the business, for the purpose of determining its effect within the company, and in the wider context of the supply chain

Parametric factory simulation for the responsive enterprise

Simulation offers a powerful way to investigate the boundaries of what can be achieved by a manufacturing system, demonstrating the impact of schedules and policy decisions such as the placement of buffers and the size of safety stocks. Unfortunately, the construction of factory models at the necessary level of detail is a time-consuming process, requiring specialist skills. This paper describes a novel approach to the representation of logistic control within a simulated factory, and its implementation in a study of a business unit at Volvo Aero in Trollhättan, Sweden. Several innovative features were built into the model, making it possible for users who were not simulation experts to explore a broad range of scenarios. The resulting model architecture, as described in this paper, takes simulation out of the computer lab and places it in the hands of managers, as an enabler of the responsive enterprise

Den onda cirkeln : en kritiskt diskursanalys av Human Rights Watchs framställning av mänskliga rättighetskränkningar i Kenya

In recent years, terror attacks in Kenya have been observed and discussed. After 9/11 Kenya has become the frontline of Africa, fighting terrorism alongside the United States. As a result of the fight against terrorism, questions regarding the treatment of Somalian refugees arise. Human Rights Watch is one of many organizations to rapport on such events for a period of time. With this in mind, the essay aims to examine how Human Rights Watch portrays the violations against Somalian refugees in Kenya and which perspective of the global responsibility for human rights is used in the reports. Through critical discourse analysis and the Framing Theory and an extensive focus on the Global Responsibility for Human Rights, my questions are answered. The material consists of three reports published by Human Rights Watch between 2010 and 2013. Through in-depth analysis of the defined problem, identification of causes, assessment of the moral, and recommendations on solutions, the study reaches the conclusion that the global responsibility of human rights is largely excluded while Kenya’s responsibility is clearly shown throughout out the reports. Thus, the portrayal shows that the country itself has the ability to solve the issue but Kenyan police and military show reluctance towards the matter. Human Rights Watch defines the problem as systematic and widespread, and that Kenya is trying to solve an issue by causing more issues. The result is an unsustainable situation with no break of the vicious cycle.Under de senaste åren har terrorattentat i Kenya uppmärksammats och diskuterats. Efter 9/11 har Kenya blivit det land i Afrika som har klassats som en frontlinje för att bekämpa terrorismen tillsammans med USA. I samband med Kenyas terrorismbekämpning har handlingar mot somaliska flyktingar ifrågasatts och Human Rights Watch är en av de organisationer som har rapporterat om händelser under en lång period. Med bakgrund av detta ämnar denna uppsats att ta reda på hur Human Rights Watch framställer de rättighetskränkningar som sker mot somaliska flyktingar i landet, samt vilket synligt perspektiv på det globala ansvaret för mänskliga rättigheter som finns i deras rapportering. En kritisk diskursanalys används som metod i denna uppsats och med hjälp utav Framing Theory, med att utökat fokus på the Global Responsibility for Human Rights besvaras mina frågeställningar. Materialet består utav tre stycken rapporter skrivna av Human Rights Watch mellan åren 2010 och 2013. Undersökningen drar slutsatsen efter att ha analyserat det definierade problemet, identifikationen av orsaker, den moraliska bedömningen och rekommendationer av lösningar, att det globala ansvaret för mänskliga rättigheter är till största del uteslutet, men Kenyans ansvar visas tydligt genom hela rapporteringen. Framställningen blir att landet har förmågan att lösa problemet men att Kenyansk polis och militär visar en ovilja att göra detta. HRW definierar problemet som systematiskt och vidsträckt och att Kenya försöker lösa ett fel med ännu ett fel. Resultatet leder till en ohållbar situation där den onda cirkeln inte bryts

Parametric factory simulation for the responsive enterprise

Simulation offers a powerful way to investigate the boundaries of what can be achieved by a manufacturing system, demonstrating the impact of schedules and policy decisions such as the placement of buffers and the size of safety stocks. Unfortunately, the construction of factory models at the necessary level of detail is a time-consuming process, requiring specialist skills. This paper describes a novel approach to the representation of logistic control within a simulated factory, and its implementation in a study of a business unit at Volvo Aero in Trollhättan, Sweden. Several innovative features were built into the model, making it possible for users who were not simulation experts to explore a broad range of scenarios. The resulting model architecture, as described in this paper, takes simulation out of the computer lab and places it in the hands of managers, as an enabler of the responsive enterprise

Alternative logistic concepts and their effect within the company and the supply chain

This document presents findings from the simulation of a focused factory at Volvo Aero, Trollhättan. A series of experiments were carried out, aimed at testing a range of alternative logistic concepts. Each concept describes an approach to the control of workflow within the business, for the purpose of determining its effect within the company, and in the wider context of the supply chain

Microstructure and magnetic properties of magnetic fluids consisting of shifted dipole particles under the influence of an external magnetic field

We investigate the structure of a recently proposed magnetic fluid consisting of shifted dipolar (SD) particles in an externally applied magnetic field via computer simulations. For standard dipolar fluids the applied magnetic field usually enhances the dipole-dipole correlations and facilitates chain formation whereas in the present system the effect of an external field can result in a break-up of clusters. We thoroughly investigate the origin of this phenomenon through analyzing first the ground states of the SD-particle systems as a function of an applied field. In a second step we quantify the microstructure of these systems as functions of the shift parameter, the effective interaction parameter, and the applied magnetic field strength. We conclude the paper by showing that with the proper choice of parameters, it is possible to create a system of SD-particles with highly interacting magnetic particles, whose initial susceptibility is below the Langevin susceptibility, and which remains spatially isotropic even in a very strong external magnetic field. © 2013 AIP Publishing LLC