Search results for "material"
showing 10 items of 32550 documents
Understanding the White-Emitting CaMoO4 Co-Doped Eu3+, Tb3+, and Tm3+ Phosphor through Experiment and Computation
2019
In this article, the synthesis by means of the spray pyrolysis method, of the CaMoO4 and rare-earth cation (RE3+)-doped CaMoO4:xRE3+ (RE3+ = Eu3+, Tb3+, and Tm3+; and x = 1, 2, and 4% mol) compounds, is presented. The as-synthesized samples were characterized using X-ray diffraction, Rietveld refinement, field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and photoluminescence (PL) spectroscopy. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, have been performed to analyze the band structure and density of states. In addition, a theoretical method based on the calculations of surface energie…
Nuove forme ed espressioni dell'architettura in terra cruda
2008
Acciaio, vetro, calcestruzzo, materie plastiche di ogni tipo sono considerati oggi, nel mondo industrializzato, materiali essenziali per la costruzione delle cosiddette “case-astronavi” realizzate nelle aree più disparate della terra, in modo selvaggio ed indiscriminato, prive di qualsiasi relazione con il contesto; edifici energivori, pressoché simili tra loro, che affidano il loro funzionamento ed il raggiungimento delle condizioni di benessere all’interno degli ambienti ad impianti tecnici sempre più sofisticati e sempre più dannosi per l’ecosistema, con ripercussioni negative sulla qualità della vita. Immagine di uno status symbol al quale oggi è sempre più difficile rinunciare. Consegu…
"Ci sono più cose in cielo e in terra..." Due metodologie diverse per investigare il passato: il Castello Nuovo di Sciacca tra storia e archeologia
2012
La storia di Sciacca e del Castello Nuovo, ricostruita sulle fonti documentarie, riceve nuova luce dalle indagini condotte dalla Soprintendenza di Agrigento nel butto del castello, che ha restituito importanti testimonianze di cultura materiale. Il contributo, attraverso la lettura sinottica dei dati archeologici ed archivistici, offre un quadro della vita quotidiana al castello tra il XIV ed il XVI secolo, quando Sciacca con il suo caricatore riveste un ruolo di primo piano nel commercio mediterraneo. The history of Sciacca and Castello Nuovo documented by archival sources and further enriched by the researches conducted by Soprintendenza of Agrigento is in the dump of the castle, which ha…
2-Methylresorcinarene: a very high packing coefficient in a mono-anion based dimeric capsule and the X-ray crystal structure of the tetra-anion
2016
Mono- and tetra-deprotonated 2-methylresorcinarene anions (1 and 2) as their trans-1,4-diammoniumcyclohexane (TDAC)2+ inclusion complexes are reported. The mono-anion forms a fully closed dimeric capsule [1·H2O·MeOH]22− with a cavity volume of 165 Å3 and (TDAC)2+ as the guest with an extremely high packing coefficient, PC = 84.2%, while the tetra-anion forms a close-packed structure with two structurally isomeric tetra-anions 2a and 2b with a 50 : 50 ratio in the crystal lattice. peerReviewed
Spin Crossover in Fe(II)–M(II) Cyanoheterobimetallic Frameworks (M = Ni, Pd, Pt) with 2-Substituted Pyrazines
2016
Discovery of spin-crossover (SCO) behavior in the family of Fe(II)-based Hofmann clathrates has led to a "new rush" in the field of bistable molecular materials. To date this class of SCO complexes is represented by several dozens of individual compounds, and areas of their potential application steadily increase. Starting from Fe(2+), square planar tetracyanometalates M(II)(CN)4(2-) (M(II) = Ni, Pd, Pt) and 2-substituted pyrazines Xpz (X = Cl, Me, I) as coligands we obtained a series of nine new Hofmann clathrate-like coordination frameworks. X-ray diffraction reveals that in these complexes Fe(II) ion has a pseudo-octahedral coordination environment supported by four μ4-tetracyanometallat…
Finite element multi-scale modeling of the failure mechanisms in a 3D woven composite
2013
International audience
Feasibility of conductive embroidered threads for I 2 C sensors in microcontroller-based wearable electronics
2023
Abstract In recent years, the importance of flexible and textile electronics in the field of wearable devices has continuously increased, as they are expected to replace conventional wires that exhibit limited resistance to the mechanical stress occurring in on-body applications. Wearable health devices (WHDs) can provide physiological information about various body parts and employ distributed sensor networks. Among the sensors typically integrated within WHDs, those based on the I2C communication protocol are very common and exploit signals transmitted at frequencies up to hundreds of kilohertz. Therefore, robust communication is required to guarantee a proper transmission of the signal a…
The Role of Textured Material in Supporting Perceptual-Motor Functions
2013
Simple deformation of the skin surface with textured materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of textured materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within …
A new constructive method of anisotropic continuous materials behavioral laws based on the theory of invariants
2010
Formation of Si/SiO2 Luminescent Quantum Dots From Mesoporous Silicon by Sodium Tetraborate/Citric Acid Oxidation Treatment
2019
We propose a rapid, one-pot method to generate photoluminescent (PL) mesoporous silicon nanoparticles (PSiNPs). Typically, mesoporous silicon (meso-PSi) films, obtained by electrochemical etching of monocrystalline silicon substrates, do not display strong PL because the silicon nanocrystals (nc-Si) in the skeleton are generally too large to display quantum confinement effects. Here we describe an improved approach to form photoluminescent PSiNPs from meso-PSi by partial oxidation in aqueous sodium borate (borax) solutions. The borax solution acts to simultaneously oxidize the nc-Si surface and to partially dissolve the oxide product. This results in reduction of the size of the nc-Si core …