The Mass-Lumped Midpoint Scheme for Computational Micromagnetics: Newton Linearization and Application to Magnetic Skyrmion Dynamics

We discuss a mass-lumped midpoint scheme for the numerical approximation of the Landau-Lifshitz-Gilbert equation, which models the dynamics of the magnetization in ferromagnetic materials. In addition to the classical micromagnetic field contributions, our setting covers the non-standard Dzyaloshinskii-Moriya interaction, which is the essential ingredient for the enucleation and stabilization of magnetic skyrmions. Our analysis also includes the inexact solution of the arising nonlinear systems, for which we discuss both a constraint-preserving fixed-point solver from the literature and a novel approach based on the Newton method. We numerically compare the two linearization techniques and show that the Newton solver leads to a considerably lower number of nonlinear iterations. Moreover, in a numerical study on magnetic skyrmions, we demonstrate that, for magnetization dynamics that are very sensitive to energy perturbations, the midpoint scheme, due to its conservation properties, is superior to the dissipative tangent plane schemes from the literature

Comparative planning and housing studies beyond taxonomy: a genealogy of the special programme for rehousing (Portugal)

Recent European comparative studies in the fields of housing policy and spatial planning have been dominated by taxonomical and linear approaches, and by normative calls for convergence toward systems considered more ‘mature’ or ‘advanced’. In this article, we adopt a genealogical perspective and consider those cultures that are central to the shaping of policy. We set out a long-term exploration of the intersection between spatial planning and housing policy in Portugal and focus on the Special Programme for Rehousing (Programa Especial de Realojamento, PER), a programme that has had changing roles (from a financial instrument to a core component of policies of urban regeneration) in connection with political and planning cultures changing in time and space. In this way, we provide evidence of the limited capacity of taxonomic and linear approaches to describe planning and housing systems undergoing processes of change and, conversely, show the potential of genealogical research.info:eu-repo/semantics/publishedVersio

Social housing policy or social policy for housing? The role of the Programa Especial de Realojamento (PER) in the housing/planning nexus in Portugal

Recent (European) comparative studies in the fields of housing policy and spatial planning have been dominated by taxonomical approaches (attempts at categorising systems and temporal stages of state action) and measures of the ‘maturity’ of national systems. In this paper, we adopt a genealogical perspective and consider (national and local) cultures central to the shaping of policy (differences and convergence). We set out a long-term, in-depth exploration of the planning-housing nexus in Portugal – a case that helps adding nuances to mainstream theorisation – and focus on the Programa Especial de Relojamento (PER; Special Programme for Rehousing), a programme that has had changing roles (from a financial instrument to a core component of policies of urban regeneration) in connection with political and planning cultures changing in time and space. Our goal is contributing to making sense of the intersection between planning cultures in transition and changing housing policy, namely the generalised shift toward regeneration and concurrent retrenchment of state action – and the relation among housing as welfare (‘social housing policy’) and housing as urban policy (‘social policy for housing’).info:eu-repo/semantics/publishedVersio

Laboratory Test Campaign Aimed at the Analysis of an Uncommon Wear Phenomenon in a Marble Quarry

The use of ornamental stones has a historical value that makes them strategically precious in Italy; marble can offer high performance in architectural applications, even though the variability of the rock mass requires detailed studies to optimize the exploitation techniques and reduce waste. Italy is world famous for its marble, which is extracted mainly through chainsaw cutting machines, which are currently used intensively due to their high‐safety working conditions compared to alternative techniques and for their great versatility, especially in underground applications. Although this cutting technique is well‐rooted, an uncommon problem of tool wear was found in the quarry under study, which strongly affected productivity. A series of laboratory test were carried out to estimate the wear potential of the rock and the suitability of the tools. The Cerchar abrasivity test highlighted a mean wear potential for the marble of 2.77, while microhardness outcomes pointed out the presence of quartz veins in the tested material (values over 10000 MPa). Finally, additives typically used in the conditioning process of EPB machines in tunneling were tested with the purpose of reducing the extent of wear. A reduction of about 50% in the wear (in terms of weight lost) was obtained for a moisture content of 9%

Age-related changes in human ceruloplasmin. Evidence for oxidative modifications.

Human plasma or serum from donors of age comprised between 15 and 95 years was analyzed for paramagnetic and total copper content, as well as for immunoreactive ceruloplasmin content and oxidase activity. All parameters were essentially unaltered, except the paramagnetic copper content, which increased 2-fold upon aging. A dramatic change of the electron paramagnetic resonance spectrum due to ceruloplasmin occurred in individuals over 65 years old and was associated with both an increase of the type 1 copper signal intensity and the appearance of new resonances of a type 2 copper species. Ceruloplasmin was isolated from either young or old donors. Spectroscopic analyses of the isolated proteins confirmed the tendency of type 1 copper to stay reduced in the "young" and oxidized in the "old" protein. The type 2 copper signal observed in most young ceruloplasmin samples was different from the species invariably present in the old protein. The magnetic parameters of the latter species were more consistent with a partially reduced trinuclear copper site. In vitro limited proteolysis resulted in identical fragmentation patterns and kinetics in both proteins. However, changes of the net electric charge were detected in the fragments of the protein isolated from aged individuals, which exhibited a carbonyl content of 0.6 mol of carbonyl/mol of protein. The same pattern of modifications, including a higher carbonyl content (0.65 versus 0.2 mol of carbonyl/mol of protein), could be reproduced by exposure of the young protein to the metal-catalyzed oxidation system iron/ascorbate. These results suggest that during aging ceruloplasmin is subjected to oxidative modifications which are likely to be the source of conformational changes around the copper sites leading to an intramolecular electron rearrangement among the various copper sites

L’utilizzo delle protesi endoscopiche nella patologia dell’apparato digerente

L’utilizzo di protesi ad introduzione per via endoscopica per patologie dell’apparato digerente sia benigne che maligne ha avuto negli ultimi anni un considerevole sviluppo. Il posizionamento delle endoprotesi è ben tollerato dai pazienti, non necessita di anestesia e comporta rischi relativamente minimi. Le nuove protesi metalliche autoespansibili permettono di risolvere stenosi anche molto serrate senza quasi mai necessità di dilatazione, con riduzione dei rischi che da questa derivano. Viene riportata una revisione dell’esperienza di protesizzazione per patologie dell’apparato digerente e vengono discussi le indicazioni, i limiti e le complicanze, sulla scorta dei dati dalla letteratura internazionale

Feeding evaluation of spontaneous species used by wild ungulates

Abandonment of traditional agricultural practices can produce remarkable effects on land use and on the vegetal composition of marginal areas. This is particularly true in the once grazed zones in the mountain environments, that are now affected by encroachment of shrubby vegetation. The conservation of these open areas and the preservation of a correct ratio pasture/wood are of extremely importance for wild animals. In this note we describe the effectiveness of agronomical intervention carried out to enhance pasture quality in a protected area of central Italy. Data collection concerned botanical composition, floristic richness and biodiversity of vegetation, before and after the intervention efforts. Moreover, data on utilization of single species were collected in order to evaluate the real consumption of each plant species by wild animals. Results confirmed the efficiency of the improvement of the studied area in terms of botanical composition and of pastoral value and they provided useful indications about the actual utilization of non forage plants by wild ungulates