Search results for "STING"
showing 10 items of 3756 documents
Nanostructuring with a crosslinkable discotic material.
2007
A high-yielding synthesis afforded a hexa-peri-hexabenzocoronene carrying acrylate units at the end of six attached alkyl spacers. The polymerization of these acrylate moieties could be initiated with thermal energy and through direct photoactivation without the addition of a photoinitiator. This allowed the organization of the liquid-crystalline material to be fixed in either the crystalline state or the mesophase, which preserved the organization in the respective phase. The use of a focused synchrotron beam permitted selected regions of a thin film to be rendered insoluble. After "developing" the film in this lithographic process by dissolving the soluble, unpolymerized material, defined…
Self-Assembled Monolayer-Functionalized Half-Metallic Manganite for Molecular Spintronics
2012
(La,Sr)MnO(3) manganite (LSMO) has emerged as the standard ferromagnetic electrode in organic spintronic devices due to its highly spin-polarized character and air stability. Whereas organic semiconductors and polymers have been mainly envisaged to propagate spin information, self-assembled monolayers (SAMs) have been overlooked and should be considered as promising materials for molecular engineering of spintronic devices. Surprisingly, up to now the first key step of SAM grafting protocols over LSMO surface thin films is still missing. We report the grafting of dodecyl (C12P) and octadecyl (C18P) phosphonic acids over the LSMO half-metallic oxide. Alkylphosphonic acids form ordered self-a…
Formation and Rupture of Schottky Nanocontacts on ZnO Nanocolumns
2007
In this paper, the electrical transport and mechanical properties of Pt/ZnO Schottky nanocontacts have been studied simultaneously during the formation and rupture of the nanocontacts. By combining multidimensional conducting scanning force spectroscopy with appropriated data processing, the physical relevant parameters (the ideality factor, the Schottky barrier height, and the rupture voltage) are obtained. It has been found that the transport curves strongly depend on the loading force. For loading forces higher than a threshold value, the transport characteristics are similar to those of large-area Schottky contact, while below this threshold deviations from strictly thermionic emission …
Comparative In Vitro Study of the Bond Strength of Composite to Carbon Fiber Versus Ceramic to Cobalt–Chromium Alloys Frameworks for Fixed Dental Pro…
2020
Purpose: The aim of this comparative in vitro study was to assess the bond strength and mechanical failure of carbon-fiber-reinforced composites against cobalt&ndash
Generation and characterization of T40/A5754 interfaces with lasers
2014
Laser-induced reactive wetting and brazing of T40 titanium with A5754 aluminum alloy with 1.5 mm thickness was carried out in lap-joint configuration, with or without the use of Al5Si filler wire. A 2.4 mm diameter laser spot was positioned on the aluminum side to provoke spreading and wetting of the lower titanium sheet, with relatively low scanning speeds (0.1 to 0.6 m/min). Process conditions did not play a very significant role on mechanical strengths, which were shown to reach 250-300 N/mm on a large range of laser power and scanning speeds. In all cases considered, the fracture during tensile testing occurred next to the TiAl3 interface, but in the aluminum fusion zone. In a second st…
Ultrasonic detection by photo-EMF sensor and by wideband air-coupled transducer
2004
Two non-contact remote ultrasonic detection systems are compared. The first consists of a continuous wave (CW) Nd:YVO4 laser operating at 532 nm used in conjunction with a photo-induced electromotive-force (EMF) sensor. The second system employs an air-coupled capacitance transducer that has a bandwidth from 100 kHz up to 2 MHz. Both systems exhibit higher sensitivity to out-of-plane than in-plane measurements of stress wave signals. Ultrasound generation is carried out by an Nd:YAG pulsed laser at 532 nm in the thermoelastic regime in a 1.6 mm aluminum plate. A0 Lamb mode is generated at frequency-thickness product with strong out-of-plane displacements. Ultrasonic waveforms acquired are r…
Beta forging of Ti-6Al-4V: Microstructure evolution and mechanical properties
2013
Titanium alloys are finding an increasing use in the aeronautical field, due to their characteristics of high mechanical properties, lightness and corrosion resistance. Moreover these alloys are compatible with the carbon fibre reinforced plastics that are also finding a wide use in the aeronautical field. On the other hand the use of these alloys implies some drawbacks, for example titanium alloys are often considered more difficult to form and generally have less predictable forming characteristics than other metallic alloys such as steel and aluminum. In this paper was studied both the microstructure evolution and the mechanical properties of a Ti-6Al-4V rolled bar after hot forging. The…
The system of carbon fibre-reinforced plastics micro-tubes for self-healing of glass fibre-reinforced plastics laminates
2016
A system of pultruded carbon fibre-reinforced plastics micro-tubes is used for self-healing simulation in laminated polymer composite. The system consists of a package of micro-tubes, placed in the symmetry plane of the GFR/epoxy laminate stack. Healing agent is a mixture of the epoxy resin and hardener. The healing agent releases and penetrates into the cracks after the composite is damaged by the quasi-static indentation. The specimens are healed at 30℃ for 24 h. Rectangular specimens notched under ASTM D2733 have been subjected to tensile test to determine interlaminar shear strength. Shear strength of specimens has been compared in three states (virgin, damaged and healed) for various …
Inverse growth transport in thermal chromia scales on Fe–15Cr steels in oxygen and in water vapour and its effect on scale adhesion
2007
Chromia scales of near equivalent thickness were thermally grown on Fe–15Cr steels in 16O2 followed by 18O2 and in H216O followed by H218O. SIMS oxygen isotope profiles showed that oxidation in oxygen proceeded by outward chromium transport, whereas oxidation in H2O involved inward transport of hydroxide species. Adhesion measurements using room temperature tensile testing could quantify adhesion energy: 20 J m−2 for O2-grown scales and 80 J m−2 for scales formed in H2O, a result of this mass transport inversion.
Beta-forging of Ti6Al4V titanium alloy powders consolidated by HIP: Plastic flow and strain-rate relation
2014
Ti6Al4V is probably the best known and studied titanium alloy, not only for aerospace applications. Nevertheless the deformation behavior still represents a challenge if any modification in the deformation process is required or introduced. This work deals with deformation behavior description of Ti6Al4V HIPped powders during high temperature deformation tests carried on in the Beta-region. Laboratory compression and tensile tests have been coupled with relaxation tests in order to achieve robust data about strain rate sensibility m-coefficient and activation energy Q. These results have been fitted for the assessment of a more general exponential deformation law. The final result is a “Dor…