Magnetic nanocomposites at microwave frequencies

Most conventional magnetic materials used in the electronic devices are ferrites, which are composed of micrometer-size grains. But ferrites have small saturation magnetization, therefore the performance at GHz frequencies is rather poor. That is why functionalized nanocomposites comprising magnetic nanoparticles (e.g. Fe, Co) with dimensions ranging from a few nm to 100 nm, and embedded in dielectric matrices (e.g. silicon oxide, aluminium oxide) have a significant potential for the electronics industry. When the size of the nanoparticles is smaller than the critical size for multidomain formation, these nanocomposites can be regarded as an ensemble of particles in single-domain states and the losses (due for example to eddy currents) are expected to be relatively small. Here we review the theory of magnetism in such materials, and we present a novel measurement method used for the characterization of the electromagnetic properties of composites with nanomagnetic insertions. We also present a few experimental results obtained on composites consisting of iron nanoparticles in a dielectric matrix.Comment: 20 pages, 10 figures, 5 table

Developing LCA-based benchmarks for sustainable consumption - for and with users

This article presents the development process of a consumer-oriented, illustrative benchmarking tool enabling consumers to use the results of environmental life cycle assessment (LCA) to make informed decisions. Active and environmentally conscious consumers and environmental communicators were identified as key target groups for this type of information. A brochure presenting the benchmarking tool was developed as an participatory, iterative process involving consumer focus groups, stakeholder workshops and questionnaire-based feedback. In addition to learning what works and what does not, detailed suggestions on improved wording and figures were obtained, as well as a wealth of ideas for future applications

Europe’s Care Regimes and the Role of Migrant Care Workers Within Them

This paper is an examination of the recent restructuring and subsequent convergence of European long-term care models. This paper also aims to highlight the increased role of migrant care workers and the need for great social and governmental recognition for all care providers. The provision of long term care is complex, divided between state, market and family providers; the state alone could not and does not act as the sole provider of care (Banks 1998). The extent to which different sectors are relied upon is largely dependent on the ideology of the country's welfare state (Timonen and Doyle 2007)

Scaling Exponents in the Incommensurate Phase of the Sine-Gordon and U(1) Thirring Models

In this paper we study the critical exponents of the quantum sine-Gordon and U(1) Thirring models in the incommensurate phase. This phase appears when the chemical potential $h$ exceeds a critical value and is characterized by a finite density of solitons. The low-energy sector of this phase is critical and is described by the Gaussian model (Tomonaga-Luttinger liquid) with the compactification radius dependent on the soliton density and the sine-Gordon model coupling constant $\beta$. For a fixed value of $\beta$, we find that the Luttinger parameter $K$ is equal to 1/2 at the commensurate-incommensurate transition point and approaches the asymptotic value $\beta^2/8\pi$ away from it. We describe a possible phase diagram of the model consisting of an array of weakly coupled chains. The possible phases are Fermi liquid, Spin Density Wave, Spin-Peierls and Wigner crystal.Comment: 10pages; Improved version; Submitted to Physical Review

Permeability of Three-Dimensional Random Fiber Webs

We report the results of essentially ab initio simulations of creeping flow through large three-dimensional random fiber webs that closely resemble fibrous sheets such as paper and nonwoven fabrics. The computational scheme used in this Letter is that of the lattice-Boltzmann method and contains no free parameters concerning the properties of the porous medium or the dynamics of the flow. The computed permeability of the web is found to be in good agreement with experimental data, and confirms that permeability depends exponentially on porosity over a large range of porosity.Peer reviewe

Identification of Clostridium species and DNA fingerprinting of Clostridium perfringens by amplified fragment length polymorphism analysis

An amplified fragment length polymorphism (AFLP) method was applied to 129 strains representing 24 different Clostridium species, with special emphasis on pathogenic clostridia of medical or veterinary interest, to assess the potential of AFLP for identification of clostridia. In addition, the ability of the same AFLP protocol to type clostridia at the strain level was assessed by focusing on Clostridium perfringens strains. All strains were typeable by AFLP, so the method seemed to overcome the problem of extracellular DNase production. AFLP differentiated all Clostridium species tested, except for Clostridium ramosum and Clostridium limosum, which clustered together with a 45% similarity level. Other Clostridium species were divided into species-specific clusters or occupied separate positions. Wide genetic diversity was observed among Clostridium botulinum strains, which were divided into seven species-specific clusters. The same AFLP protocol was also suitable for typing C. perfringens at the strain level. A total of 29 different AFLP types were identified for 37 strains of C. perfringens; strains initially originating from the same isolate showed identical fingerprinting patterns and were distinguished from unrelated strains. AFLP proved to be a highly reproducible, easy-to-perform, and relatively fast method which enables high throughput of samples and can serve in the generation of identification libraries. These results indicate that the AFLP method provides a promising tool for the identification and characterization of Clostridium species

Interaction Properties of the Periodic and Step-like Solutions of the Double-Sine-Gordon Equation

The periodic and step-like solutions of the double-Sine-Gordon equation are investigated, with different initial conditions and for various values of the potential parameter $\epsilon$. We plot energy and force diagrams, as functions of the inter-soliton distance for such solutions. This allows us to consider our system as an interacting many-body system in 1+1 dimension. We therefore plot state diagrams (pressure vs. average density) for step-like as well as periodic solutions. Step-like solutions are shown to behave similarly to their counterparts in the Sine-Gordon system. However, periodic solutions show a fundamentally different behavior as the parameter $\epsilon$ is increased. We show that two distinct phases of periodic solutions exist which exhibit manifestly different behavior. Response functions for these phases are shown to behave differently, joining at an apparent phase transition point.Comment: 17pages, 15 figure

Twisting Graphene Nanoribbons into Carbon Nanotubes

Although carbon nanotubes consist of honeycomb carbon, they have never been fabricated from graphene directly. Here, it is shown by quantum molecular-dynamics simulations and classical continuum-elasticity modeling, that graphene nanoribbons can, indeed, be transformed into carbon nanotubes by means of twisting. The chiralities of the tubes thus fabricated can be not only predicted but also externally controlled. This twisting route is an opportunity for nanofabrication, and is easily generalizable to ribbons made of other planar nanomaterials.Comment: 9 pages, 10 figure

Thinking about Later Life: Insights from the Capability Approach

A major criticism of mainstream gerontological frameworks is the inability of such frameworks to appreciate and incorporate issues of diversity and difference in engaging with experiences of aging. Given the prevailing socially structured nature of inequalities, such differences matter greatly in shaping experiences, as well as social constructions, of aging. I argue that Amartya Sen’s capability approach (2009) potentially offers gerontological scholars a broad conceptual framework that places at its core consideration of human beings (their values) and centrality of human diversity. As well as identifying these key features of the capability approach, I discuss and demonstrate their relevance to thinking about old age and aging. I maintain that in the context of complex and emerging identities in later life that shape and are shaped by shifting people-place and people-people relationships, Sen’s capability approach offers significant possibilities for gerontological research