Search results for "Rut"
showing 10 items of 2295 documents
An investigation into the fracture behaviour of honeycombs with density gradients
2020
International audience; In this study we perform an experimental and computational investigation about the fracture behaviour of polymer honeycombs presenting gradients in terms of lattice density. Such lattice relative density variations are introduced with the aim of mimicking the micro-morphology encountered in some natural materials, such as several kinds of woods, which seems related to the ability of the corresponding macro-material to delay the propagation of fracture under certain conditions. Starting from the conclusions of previous computational analyses, we perform a few experimental tensile tests on ABS model honeycombs obtained by additive manufacturing, with the aim of getting…
The interdependence of structural and electrical properties in TiO2/TiO/Ti periodic multilayers
2013
International audience; Multilayered structures with 14-50 nm periods composed of titanium and two different titanium oxides, TiO and TiO2, were accurately produced by DC magnetron sputtering using the reactive gas pulsing process. The structure and composition of these periodic TiO2/TiO/Ti stacks were investigated by X-ray diffraction and transmission electronic microscopy techniques. Two crystalline phases, hexagonal close packed Ti and face centred cubic TiO, were identified in the metallic-rich sub-layers, whereas the oxygen-rich ones comprised a mixture of amorphous TiO2 and rutile phase. DC electrical resistivity rho measured for temperatures ranging from 300 to 500 K exhibited a meta…
Effect of oxidation post treatments on TiO2 coating manufactured using reactive very low-pressure plasma spraying (R-VLPPS)
2020
Abstract TiO2 coatings manufactured using reactive very low-pressure plasma spraying (R-VLPPS) were analyzed in different regions related to their position compared to the plasma flame. For that, a screen was used in order to hide an area of the substrate from the direct plasma flux. The coating morphology changed from quasi lamellar structure to highly vapor structure and coatings exhibited obvious modifications in terms of phases and mechanical properties. The effect of oxidation post treatment on the as sprayed coating was then studied by selecting two methods: in situ oxidation post treatment and classical thermal treatment. The two post treatments provided an increase of the main rutil…
Influence of surface topography on depth profiles obtained by Rutherford backscattering spectrometry
2000
A method for determining correct depth profiles from samples with rough surfaces is presented. The method combines Rutherford backscattering spectrometry with atomic force microscopy. The topographical information obtained by atomic force microscopy is used to calculate the effect of the surface roughness on the backscattering spectrum. As an example, annealed Au/ZnSe heterostructures are studied. Gold grains were observed on the surfaces of the annealed samples. The annealing also caused diffusion of gold into the ZnSe. Backscattering spectra of the samples were measured with a 2 MeV 4He+ ion beam. A scanning nuclear microprobe was used to verify the results by measuring backscattering fro…
Lattice sites of diffused gold and platinum in epitaxial ZnSe layers
2000
Abstract The lattice location of diffused gold and platinum in zinc selenide (ZnSe) epitaxial layers was studied using the Rutherford backscattering (RBS) channeling technique. Thin Au and Pt films were evaporated onto ZnSe samples. The Au/ZnSe samples were annealed at 525°C and the residual Au film was removed by etching. Channeling angular scan measurements showed that about 30% of Au atoms were close to substitutional site (displaced about 0.2 A). In the case of the Pt/ZnSe samples the annealing temperatures ranged from 600°C to 800°C. The Pt minimum yields along 〈1 0 0〉 direction were close to the random value, varying from 80% to 90%. The measured Pt angular scans along 〈1 0 0〉 and 〈1 …
A New LA ‐ ICP ‐ MS Method for Ti in Quartz: Implications and Application to High Pressure Rutile‐Quartz Veins from the Czech Erzgebirge
2016
Experimental determination of the pressure and temperature controls on Ti solubility in quartz provides a calibration of the Ti-in-quartz (TitaniQ) geothermometer applicable to geological conditions up to ~ 20 kbar. We present a new method for determining 48Ti mass fractions in quartz by LA-ICP-MS at the 1 μg g−1 level, relevant to quartz in HP-LT terranes. We suggest that natural quartz such as the low-CL rims of the Bishop Tuff quartz (determined by EPMA; 41 ± 2 μg g−1 Ti, 2s) is more suitable than NIST reference glasses as a reference material for low Ti mass fractions because matrix effects are limited, Ca isobaric interferences are avoided, and polyatomic interferences at mass 48 are i…
The photochemistry of mono- and dinuclear cyclometalated bis(tridentate)ruthenium(ii) complexes: dual excited state deactivation and dual emission
2016
The synthesis and characterization of a series of weakly emissive mononuclear cyclometalated [Ru(dpb-R)(tpy)](+) complexes with functional groups R of varying electron-donating characters at the dpb ligand are described (dpbH = 1,3-di(2-pyridyl)benzene, tpy = 2,2';6',2''-terpyridine, 1(+): R = NHCOMe, 2(+): R = NH2, 3(+): R = COOEt, 4(+): R = COOH). Steady-state emission spectroscopy in the temperature range between 298 K and 77 K revealed a previously unrecognized excited state deactivation pathway via low-lying triplet ligand-to-ligand ((3)LL'CT) charge transfer states in addition to the well-known pathway via(3)MC states. Thermal activation barriers for depopulation of the emissive metal…
Cross-Metathesis/Intramolecular (Hetero-)Michael Addition: A Convenient Sequence for the Generation of Carbo- and Heterocycles
2017
The high stability and functional group compatibility of ruthenium carbene complexes confer them a great ability to catalyze domino processes. For this reason, the combination of metathesis reactions with additional transformations in a domino fashion has been exploited extensively, with the result of expanding the utility of ruthenium carbene complexes beyond that of just olefin metathesis. Among those domino processes, it is worth mentioning the sequence of cross-metathesis/intramolecular Michael addition, which allows for the generation of a wide variety of carbo- and heterocycles in a very simple manner, taking advantage of the benefits of domino reactions. Carbon-, oxygen- and nitrogen…
Highly antiproliferative neutral Ru(ii)-arene phosphine complexes
2018
Six ruthenium(II)- and four gold(I)-phosphine based complexes were synthesized and fully characterized. Some of them displayed strong antiproliferative properties for several types of cancer including colon, breast, and lung. Notably, two of the Ru(II) complexes displayed an IC50 of around 2 μM, which is exceptional for these types of complexes. The dramatic impact of the nature of the arene coordinated on the ruthenium center was clearly evidenced.
Boulder coastal deposits at Favignana Island rocky coast (Sicily, Italy): Litho-structural and hydrodynamic control
2018
Boulders are frequently dislodged from rock platforms, transported and deposited along coastal zones by high-magnitude storm waves or tsunamis. Their size and shape are often controlled by the thickness of bedding planes as well as by high-angle to bedding fracture network. We investigate these processes along two coastal areas of Favignana Island by integrating geological data for 81 boulders, 49 rupture surfaces (called sockets) and fracture orientation and spacing with four radiocarbon dates, numerical hydrodynamic analysis, and hindcast numerical simulation data. Boulders are scattered along the carbonate platform as isolated blocks or in small groups, which form, as a whole, a disconti…