The Role of Anisotropy in Distinguishing Domination of Néel or Brownian Relaxation Contribution to Magnetic Inductive Heating: Orientations for Biomedical Applications

Magnetic inductive heating (MIH) has been a topic of great interest because of its potential applications, especially in biomedicine. In this paper, the parameters characteristic for magnetic inductive heating power including maximum specific loss power (SLPmax), optimal nanoparticle diameter (Dc) and its width (ΔDc) are considered as being dependent on magnetic nanoparticle anisotropy (K). The calculated results suggest 3 different Néel-domination (N), overlapped Néel/Brownian (NB), and Brownian-domination (B) regions. The transition from NB- to B-region changes abruptly around critical anisotropy Kc. For magnetic nanoparticles with low K (K Kc) are opposite. The decreases of the SLPmax when increasing polydispersity and viscosity are characterized by different rates of d(SLPmax)/dσ and d(SLPmax)/dη depending on each domination region. The critical anisotropy Kc varies with the frequency of an alternating magnetic field. A possibility to improve heating power via increasing anisotropy is analyzed and deduced for Fe3O4 magnetic nanoparticles. For MIH application, the monodispersity requirement for magnetic nanoparticles in the B-region is less stringent, while materials in the N- and/or NB-regions are much more favorable in high viscous media. Experimental results on viscosity dependence of SLP for CoFe2O4 and MnFe2O4 ferrofluids are in good agreement with the calculations. These results indicated that magnetic nanoparticles in the N- and/or NB-regions are in general better for application in elevated viscosity media

False vacuum energy dominated inflation with large rr and the importance of κs\kappa_s

We investigate to which extent and under which circumstances false vacuum energy ($V_0$) dominated slow-roll inflation is compatible with a large tensor-to-scalar ratio $r = O(0.1)$, as indicated by the recent BICEP2 measurement. With $V_0$ we refer to a constant contribution to the inflaton potential, present before a phase transition takes place and absent in the true vacuum of the theory, like e.g. in hybrid inflation. Based on model-independent considerations, we derive an upper bound on the possible amount of $V_0$ domination and highlight the importance of higher-order runnings of the scalar spectral index (beyond $\alpha_s$) in order to realise scenarios of $V_0$ dominated inflation. We study the conditions for $V_0$ domination explicitly with an inflaton potential reconstruction around the inflaton field value 50 e-folds before the end of inflation, taking into account the present observational data. To this end, we provide the up-to-date parameter constraints within $\Lambda$CDM + $r$ + $\alpha_s$ + $\kappa_s$ using the cosmological parameter estimation code Monte Python together with the Boltzmann code CLASS.Comment: 16 pages, 5 figures; v2: matches publication in JCA

The law of corporate groups in Portugal

After the pioneering German “Aktiengesetz” of 1965 and the Brazilian “Lei das Sociedades Anónimas” of 1976, Portugal has become the third country in the world to enact a specific regulation on groups of companies. The Code of Commercial Companies (“Código das Sociedades Comerciais”, abbreviately hereinafter CSC), enacted in 1986, contains a unitary set of rules regulating the relationships between companies, in general, and the groups of companies, in particular (arts. 481° to 508°-E CSC). With this set of rules, the Portuguese legislator has dealt with one of the major topics of modern Company Law. While this branch of law is traditionally conceived as the law of the individual company, modern economic reality is characterized by the massive emergence of large-scale enterprise networks, where parts of a whole business are allocated and insulated in several legally independent companies submitted to an unified economic direction. As Tom HADDEN put it: “Company lawyers still write and talk as if the single independent company, with its shareholders, directors and employees, was the norm. In reality, the individual company ceased to be the most significant form of organization in the 1920s and 1930s. The commercial world is now dominated both nationally and internationally by complex groups of companies”. This trend, which is now observable in any of the largest economies in the world, holds also true for small markets such as Portugal. Although Portuguese economy is still dominated by small and medium-sized enterprises, the organizational structure of the group has always been extremely common. During the 70s, it was estimated that the seven largest groups of companies owned about 50% of the equity capital of all domestic enterprises and were alone responsible for 3/4 of the internal national product. Such a trend has continued and even highlighted in the next decades, surviving to different political and economic scenarios: during the 80s, due to the process of state nationalization of these groups, an enormous public group with more than one thousand controlled companies has been created (“IPE - Instituto de Participações do Estado”); and during the 90s until today, thanks to the reprivatisation movement and the opening of our national market, we assisted to the re-emergence of some large private groups, composed of several hundred subsidiaries each, some of which are listed in foreign stock exchange markets (e.g., in the banking sector, “BCP – Banco Comercial Português”, in the industrial area, “SONAE”, and in the media and communication area, “Portugal-Telecom”)