Search results for " layers"
showing 10 items of 91 documents
Developing REE parameters for soil and sediment profile analysis to identify Neolithic anthropogenic signatures at Serpis Valley (Spain)
2020
In this study, patterns of rare earth elements (REE) have been developed and applied for the first time to sediments and soils to identify anthropogenic or natural layers in profiles sampled at several Neolithic settlements in the Serpis Valley area (Alicante, Spain). Most of these sites are characterized by dark brown paleosols that are easily distinguishable from the light brown paleosols of the valley. To demonstrate whether these strata are anthropogenic or natural requires a better geochemical understanding of sediment. Soil samples were taken across six different sites; four sites are associated with archaeological findings (sites BF, LP, PB and AC8); another one is from a natural sec…
The ancient urban agroforestry systems of the Conca D'Oro (Palermo, Italy) need protection to defend the city
2019
The favorable environmental conditions together with the ancient agronomic practices, e.g. the irrigation systems introduced by the Arabs, have made the plain surrounding Palermo, known as Conca d’Oro, the unique agriculture landscape famous worldwide. Several tree and vegetable species have spread throughout in time but the new crops, instead of replacing the others, were often integrated exploiting the different heights of the tree canopies. The result was the creation of complex agroecosystems characterized by orchards with several layers of trees (as walnut, loquat, citrus) and empty spaces where the farmers cultivated vegetables. The grass fed the animals in the stables while manure wa…
Deposition and production of highly reproducible hybrid Cu[(tBu)4Pc]-polystyrene thin layers via spin casting
2012
This study focuses on the determination of a protocol for the production of a hybrid material composed of a polymer and a macrocyclic complex, namely polystyrene and a tetra-tert-butyl-copper phthalocyanine (Cu[(tBu)4Pc]), in order to obtain a layer thickness of about 100 nm and a controlled porosity in a highly reproducible way. Several methods were implemented and their reproducibility was evaluated through elements of characterization such as optical microscopy, atomic force microscopy and scanning electron microscopy. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers
Orientation of Polymer Functionalized Nanorods in Thin Films
2010
A directed self assembly of anisotropic nanostructures offers a possibility to provide unique functional materials, which are e.g., important in optoelectronic devices. We use the liquid crystalline behavior of polymer functionalized TiO2 and ZnO nanorods to apply methods well known for low molecular liquid crystals to achieve oriented thin films. Convective forces in the meniscus on a structured substrate obtain thin layers of oriented nanoparticles with a ordering parameter of S = 0.7. As another method we present the orientation of polystyrene covered ZnO nanorods under an applied electric field. The method offers a perpendicular alignment of the rods to the surface.
Effects of VTE Treatment on Composition of Lithium Tantalate Single Crystals
2011
The vapour transport equilibration (VTE) is used to change the Li/Ta ratio in lithium tantalate single crystals of different crystallographic orientations (Z-cut and Y/128°-cut). Treatment by VTE is shown to provide thin layers in lithium tantalate plates composition of which is close to stoichiometric while the values of the coercive field are different, much smaller compared with congruent single crystals. There are several mechanisms of diffusion of the Li+ ions in LiTaO3 under conditions of VTE the contribution of each being dependent on the crystallographic orientation of the sample.
Electron Irradiation Effects on Single‐Layer MoS 2 Obtained by Gold‐Assisted Exfoliation
2022
International audience; Mechanical exfoliation assisted by gold is applied to obtain good quality large lateral size single-layer MoS2. The effects of 2.5 MeV electron irradiation are investigated at room temperature on structural and electronic features by Raman and microluminescence spectroscopy. The exciton recombination emission in the direct bandgap of single-layer MoS2 is affected during irradiation starting from the minimum explored dose of 1 kGy. At higher doses, Raman bands show no relevant modifications whereas the exciton emission is quenched, suggesting that irradiation-induced point defects affect exciton dynamics.
Astronomical dating of two Pliocene alkaline volcanic ash layers in the Capo Rossello area (southern Sicily, Italy): implications for the beginning o…
2009
Key-words. - Sicily Channel rift, Biostratigraphy, Astronomical calibration, Pliocene, Volcanic ash layers. Abstract. - Two volcaniclastic ash layers (AL1 and AL2) are intercalated throughout the middle Pliocene sedimentary sequences of Punta Piccola and Capo Rossello exposed along the south coast of Sicily (Italy). Astronomical calibration of the Punta Piccola section provided an age of 2.676 Ma for the deposition of the AL1 layer. The high-resolution bio-cyclostratigraphy of the Capo Rossello section, in combination with detailed correlations with previously astrono- mically calibrated coeval sequences, provided an age of 2.225 Ma for the deposition of the AL2 layer. Mineralogical, petrog…
Highly Active and Stable NiCuMo Electrocatalyst Supported on 304 Stainless Steel Porous Transport Layer for Hydrogen Evolution in Alkaline Water Elec…
2023
Several functionalized porous transport layers with Pt-free electrocatalysts for hydrogen evolution reaction in alkaline conditions, based on Ni, Cu, and Mo, are prepared through electrodeposition onto a 304 stainless steel mesh. Morphological characterization confirms the fabrication of electrodes with high electrochemical surface active area due to the formation of hierarchical nanostructures. Mo presence into the electrocatalysts increases the activity toward the hydrogen evolution reaction. The optimization of electrodeposition process leads to the preparation of highly active NiCuMo electrocatalyst that exhibits near zero onset overpotential and overpotentials of 15 and 113 mV at 10 an…
La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde
2022
Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…
Many witnesses, many layers: the digital scholarly edition of the Iudicium coci et pistoris (Anth. Lat. 199 Riese)
2014
Il progetto di ricerca messo in cantiere durante l'anno della mia borsa di studio post-doc presso il Centro Linceo Interdisciplinare “B. Segre” dell'Accademia dei Lincei prevede la creazione di un'edizione critica digitale del Iudicium coci et pistoris iudice Vulcano di Vespa (Anth. Lat. 199 Riese), un testo latino tardoantico in versi con una tradizione pluritestimoniale. Tale edizione intende mettere a frutto gli apporti della semiotica, della linguistica e di quella sua parte detta grafologia, applicando le intuizioni teoriche e metodologiche di Tito Orlandi (vd. in particolare Informatica testuale, Laterza: Roma 2010); ed applicare, innovandolo, il markup XML/TEI. In tale edizione, le f…