Search results for "walls"
showing 9 items of 49 documents
Imaging Spin Dynamics on the Nanoscale Using X-Ray Microscopy
2015
The dynamics of emergent magnetic quasiparticles, such as vortices, domain walls and bubbles are studied by scanning transmission X-ray microscopy (STXM), combining magnetic (XMCD) contrast with about 25 nm lateral resolution as well as 70 ps time resolution. Essential progress in the understanding of magnetic vortex dynamics is achieved by vortex core reversal observed by sub-GHz excitation of the vortex gyromode, either by ac magnetic fields or spin transfer torque. The basic switching scheme for this vortex core reversal is the generation of a vortex-antivortex pair. Much faster vortex core reversal is obtained by exciting azimuthal spin wave modes with (multi-GHz) rotating magnetic fiel…
La costruzione del paesaggio ibleo: reti deboli, segni forti
2017
The contribution deals with the theme of the dry stone walls’ landscape which characterizes the rural “Koinè” of the Hyblean plateau in South-Eastern Sicily. The essay analyses the main political-economic, social-territorial, constructive and typological features which make the dry walls network the landmark of the Ragusa province. Because of the modification of the economic-cultural context that produced it, the loss of knowledge of the construction techniques and the lack of public resources, the definition of an axiology of the contemporary landscape as premise for the establishment of adequate terms of value for the safeguard of this heritage is required.
Earth in Sicilian walls: notes in progress
2011
Il saggio, inserito nel volume in doppia lingua "Architetture in terra nell'Italia del Sud", ricostruisce alcuni degli episodi e delle prassi costruttive che in Sicilia hanno visto l'uso della terra cruda nelle costruzioni edilizie. Utilizzando fonti archivistiche, bibliografiche e dirette su manufatti ancora esistenti, lo scritto ritrova la terra nei modi del fabbricare dal Cinquecento ai primi anni del Novecento, da Messina a Palermo, per la formazione di mattoni o per la muratura in "pietra e tajo", così diffusa e poco conosciuta da determinare difficoltà di interpretazione e di intervento.
Contributo alla conoscenza delle proprietà termofisiche delle murature storiche palermitane
2014
This paper presents the preliminary findings of in situ measurements of thermal transmittance taken in a monumental complex in Palermo. The objective of energy efficiency, one of the main aspects of sustainable construction, is now relevant also for historic architecture. The research aims at analysing the energy performance of the stone walls of the complex, characterized by various thickness, age and construction features. Measurements are taken in accordance with the international standard ISO 9869:1994. The U-values so obtained are compared with tabular data from the Italian standard UNI/TS 11300-1:2008 and with values calculated following the UNI EN ISO 6946:2008. Nine preliminary meas…
Domain wall motion in a diffusive weak ferromagnet
2019
We study the domain wall motion in a disordered weak ferromagnet, induced by injecting a spin current from a strong ferromagnet. Starting from the spin diffusion equation describing the spin accumulation in the weak ferromagnet, we calculate the force and torque acting on the domain wall. We also study the ensuing domain wall dynamics, and suggest a possible measurement method for detecting the domain wall motion via measuring the additional resistance.
Flexural behaviour of calcarenite masonry walls reinforced with FRP sheets
2015
The use of fiber-reinforced polymers (FRP) for structural strengthening has become increasingly popular in recent years. Several applications of FRP have been proposed and applied, depending on the target of the technique, kind and/or material of the structural member. In particular, because of their great tensile strength, FRP materials are commonly used to enhance the out-of-plane behaviour of masonry walls, allowing to increase their strength, ductility and improving safety against overturning. For these reasons, FRP laminates are often applied in vulnerable ancient buildings in seismic areas to reinforce façades and walls with poor structural features. However, some issues arise when ad…
The use of pumice lightweight concrete for masonry applications
2011
In the last two decades, the use of pumice as lightweight aggregate for concrete in structural applications has been the object of different studies. The aim was to find out if pumice can be an alternative to ordinary lightweight aggregate. The present paper is framed in this context. Here, a study is presented showing the use of pumice for making lightweight concrete units for masonry members. Through the paper, the formulation of a mix design for lightweight concrete is proposed. Then the obtained mechanical characteristics of the masonry units are discussed and compared to the code requirements. Reinforced bearing masonry walls, made with the concrete masonry units in question, were made…
Riqualificazione e sostenibilità - L’involucro verde come campo privilegiato di sperimentazione tecnologica.
2015
The study of the housing green for the redevelopment of the buildings along with the testing of innovative products for the realization of vertical gardens and the design of guidelines for the construction and environmental transformation of the waterfront of Marina Todaro of Palma di Montechiaro "act as instruments to define the possible prospects to Palma di Montechiaro can apply for green city of the Province of Agrigento, exploring scenarios still little practiced in this context and in the short and medium term can be attributed character priority ". The originality of this research is also experienced in site participatory approach with the participation of the inhabitants, considered…
Effet colloide-protecteur d'extraits de parois de levures sur la stabilité tartrique d'une solution hydro-alcoolique modèle
1993
<p style="text-align: justify;">L'effet colloïde-protecteur d'extraits mannoprotéiques de parois de levures vis-à-vis de la précipitation tartrique a été étudié en solution hydroalcoolique, en utilisant un IST mètre (Indice de Stabilité Tartrique).</p><p style="text-align: justify;">Nous avons montré que les deux extraits levuriens inhibaient la cristallisation du bitartrate de potassium au même titre que l'acide métatartrique et la carboxyméthylcellulose, mais à un niveau plus faible. Le niveau de stabilité retenu (ISTC-75) est assuré avec des concentrations par litre de 7,5 mg d'acide métatartrique et de 18 mg de carboxyméthylcellulose. Des concentrations en extraits man…