64 research outputs found
Spin density and state of order in the alloy Ni78Mn22
No full textThe experimentally measured spin density of a partially ordered Ni78Mn22 alloy is used to study the magnetic state of Mn within an fcc environment. The present data, together with those obtained by Petrillo, Sacchetti, and Scafi [Phys. Rev. 44, 9418 (1991)), are used to determine the form factor and magnetic moment of the Mn atoms in various atomic configurations. It is found that Mn carries a magnetic moment with fluctuating spin, while an appreciable charge transfer from Mn to Ni is suggested
Low-code design of collective systems with ScaFi-Blocks
No full textScaFi-Blocks is a visual, low-code programming environment for designing and implementing swarm algorithms. Built on the ScaFi aggregate computing framework and the Blockly visual programming library, ScaFi-Blocks enables users to visually compose algorithms using intuitive building blocks, abstracting away the complexities of traditional swarm programming frameworks. This approach simplifies the development of collective behaviours for a wide range of swarm systems, including robot swarms, IoT device ensembles, and sensor networks, fostering broader accessibility and innovation within the field. This contribution bridges the gap between visual programming and textual code, lowering the barrier to entry for non-experts while promoting a deeper understanding of aggregate computing principles
Spin density in MnNi3.55: A magnetic state of fcc manganese
No full textThe magnetic structure factors determined using polarized-neutron scattering have been employed to analyze the magnetic-moment distribution of Mn in MnX3 alloys (X = Ni,Pt). In particular, a spin-density measurement in MnNi3.55 at a low degree of long-range order has been performed at room temperature. Results suggest that Mn is found in a high-magnetic-moment state in this class of compounds, independently of the system, thus indicating a small dependence of the magnetic state on the atomic volume. Furthermore, a rather direct evidence of the presence of Mn atoms having a negative magnetic moment is also obtained. The information, which can be derived on the electron distribution in fcc Mn, is also discussed in a phenomenological fashion
ScaFi-Web: A Web-Based Application for Field-Based Coordination Programming
No full textField-based coordination is a model for expressing the coordination logic of large-scale adaptive systems, composing functional blocks from a global perspective. As for any coordination model, a proper toolchain must be developed to support its adoption across all development phases. Under this point of view, the ScaFi toolkit provides a coordination language (field calculus) as a DSL internal in the Scala language, a library of reusable building blocks, and an infrastructure for simulation of distributed deployments. In this work, we enrich such a toolchain by introducing ScaFi-Web, a web-based application allowing in-browser editing, execution, and visualisation of ScaFi programs. ScaFi-Web facilitates access to the ScaFi coordination technology by flattening the learning curve and simplifying configuration and requirements, thus promoting agile prototyping of field-based coordination specifications. In turn, this opens the door to easier demonstrations and experimentation, and also constitutes a stepping stone towards monitoring and control of simulated/deployed systems
ScaFi-Blocks: A Visual Aggregate Programming Environment for Low-Code Swarm Design
No full textSwarm programming is focused on the design and implementation of algorithms for large-scale systems, such as fleets of robots, ensembles of IoT devices, and sensor networks. Writing algorithms for these systems requires skills and familiarity with programming languages, which can be a barrier for non-expert users. Even if visual programming environments have been proposed for swarm systems, they are often limited to specific platforms or tasks, and do not provide a high-level programming model that can be used to design algorithms for a wide range of swarm systems. Therefore, in this paper, we propose a low-code swarm programming environment, called ScaFi-Blocks, which allows users to design and implement swarm algorithms visually. ScaFi-Blocks is based on the ScaFi aggregate computing framework, which provides a high-level programming model for the design of distributed algorithms. Aggregate computing is based on the concept of field-based coordination, and it allows users to design algorithms by composing simple building blocks, which motivates the design of the proposed artefact. The environment is designed to be user-friendly and to support the design of a wide range of collective applications. In this paper, we present the architecture of ScaFi-Blocks, discuss its features and capabilities, and provide a preliminary evaluation of the programming environment based on a case study featuring articulated swarm behaviour
Alessandro Scafi (éd.), The Cosmography of Paradise : The Other World from Ancient Mesopotamia to Medieval Europe
No full textLa notion de paradis, présente de façon plus ou moins affirmée dans toutes les cultures influencées par le Moyen Orient, est examinée dans cet ouvrage en une suite de monographies introduites par Alessandro Scafi. Sont ainsi successivement présentés la Mésopotamie ancienne (M. J. Geller), l’Iran pré-islamique (A. C. D. Panaino), les débuts de la cosmographie juive (A. Y. Reed), les paradis de la Gnose (E. Thomassen), le dualisme médiéval et ses origines juives (Y. Stoyanov), les conceptions d..
SILAC-based complexome profiling dissects the structural organization of the human respiratory supercomplexes in SCAFIKO cells
No full textThe study of the mitochondrial respiratory chain (MRC) function in relation with its structural organization is of great interest due to the central role of this system in eukaryotic cell metabolism. The complexome profiling technique has provided invaluable information for our understanding of the composition and assembly of the individual MRC complexes, and also of their association into larger supercomplexes (SCs) and respirasomes. The formation of the SCs has been highly debated, and their assembly and regulation mechanisms are still unclear. Previous studies demonstrated a prominent role for COX7A2L (SCAFI) as a structural protein bridging the association of individual MRC complexes III and IV in the minor SC III2 + IV, although its relevance for respirasome formation and function remains controversial. In this work, we have used SILAC-based complexome profiling to dissect the structural organization of the human MRC in HEK293T cells depleted of SCAFI (SCAFI(KO)) by CRISPR-Cas9 genome editing. SCAFI ablation led to a preferential loss of SC III2 + IV and of a minor subset of respirasomes without affecting OXPHOS function. Our data suggest that the loss of SCAFI-dependent respirasomes in SCAFI(KO) cells is mainly due to alterations on early stages of CI assembly, without impacting the biogenesis of complexes III and IV. Contrary to the idea of SCAFI being the main player in respirasome formation, SILAC-complexome profiling showed that, in wild-type cells, the majority of respirasomes (ca. 70%) contained COX7A2 and that these species were present at roughly the same levels when SCAFI was knocked-out. We thus demonstrate the co-existence of structurally distinct respirasomes defined by the preferential binding of complex IV via COX7A2, rather than SCAFI, in human cultured cells
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