3,312,755 research outputs found
Embedded layer of Ag nanoparticles prepared by a combined PECVD/PVD process producing SiOxCy-Ag nanocomposite thin films.
No full textStructural properties of SiOxCy–Ag nanocomposite thin films prepared by a dual process PVD–PECVD in the same reactor have been investigated. The experimental results have demonstrated the influence of a PECVD process carried out at room temperature for the growth of a dielectric matrix on the size and the distribution density of Ag nanoparticles (NPs) deposited beforehand by magnetron sputtering. The plasma during the growth of the encapsulation SiOxCy layer caused a diffusion of silver from NPs through the SiOxCy matrix associated with a decrease in the average size of nanoparticles and an increase of their distribution density. Silver diffusion is blocked at a barrier interface to form a buried layer of individual Ag NPs which, for instance, can find plasmonic applications. Silver also diffuses toward the outer surface inducing antibacterial properties. In both cases initial Ag NPs act as reservoirs for multifunctional properties of advanced nanostructured films
Accelerated bacterial reduction on Ag–TaN compared with Ag–ZrN and Ag–TiN surfaces
No full textAg–TaN sputtered on polyester (PES) accelerated >6 times the bacterial inactivation kinetics compared to TaN–PES under actinic light irradiation. Direct current pulsed magnetron sputtering (DCP) was used to sputter Ag–TaN–PES and TaN–PES. Complete bacterial reduction by Ag–TaN occurred within 20 min compared to Ag–TiN (100 min) and Ag–ZrN (90 min). The co-sputtering of Ag and Ta on PES was carried out in an Ar/N2 10% atmosphere. By ion-coupled plasma mass-spectrometry (ICP–MS) a reduced Ag-release was observed for Ag–TaN samples compared to Ag–PES samples within the disinfection period. The redox catalysis by the Ag-species during the bacterial disinfection was followed by X-ray photoelectron spectroscopy (XPS). A bacterial reduction mechanism is suggested consistent with the experimental findings. The nitride films were characterized by surface science methods.GPA
Wetting and interactions of Ag–Cu–Ti and Ag–Cu–Ni alloys with ceramic and steel substrates for use as sealing materials in a DCFC stack
No full textThe authors would like acknowledge the financial support received from the Engineering and Physical Sciences Research Council [EP/K015540/1] and the European Coal and Steel Community [RFCR-CT-2011-00004].Ag and Ag-based pseudo-alloys were evaluated in terms of application as metal brazes for the use in a hybrid direct carbon fuel cell stack. This paper reports on a series of wetting experiments on systems of pure Ag as well as Ag–Cu–Ti and Ag–Cu–Ni pseudo-alloys in contact with the widely used austenitic stainless steel SS316L, the ferritic steels Crofer22APU and Croffer22H and with polycrystalline partially stabilized zirconia (TZ-3Y) for the determination of the interfacial properties of the above systems. Pure Ag in air showed poor wettability (θ >90°) with all substrates. The Ag–Cu–Ti pseudo-alloy in vacuum (P = 2.5 x 10-3 mbar) showed improved wettability, with θ = 40°. for the steels and θ =50°. for the TZ-3Y substrates. The Ag–Cu–Ni pseudo-alloy in air showed excellent wetting properties (θ <10°) with all the substrates, but its high liquidus temperature makes it unsuitable for use with the SS316L steel. In low vacuum (P = 1.5 x 10-1 mbar), the contact angle was increased (θ = 65°) but the low oxygen concentration limits the oxidation of the steel surface. Selected systems of the pseudo-alloys in contact with steel and TZ-3Y substrates were treated for 120 h in the operating conditions of a hybrid direct carbon fuel cell, in order to evaluate the thermal stability of the joints. Despite the reactions taking place on the interface, the joints showed good stability and no separation of the two phases occurred.Peer reviewe
Coverage dependence of the spin-resolved photoemission from epitaxially grown Ag layers on Pt(111)
No full textSchmiedeskamp B, Kessler B, Vogt B, Heinzmann U. Coverage dependence of the spin-resolved photoemission from epitaxially grown Ag layers on Pt(111). Surface Science. 1989;223(3):465-478.Ag/Pt(111) has been studied by spin-, angle-, and energy-resolved photoemission with circularly polarized synchrotron radiation of BESSY for different Ag coverages. The prepared layers were characterized by AES and LEED and turned out to grow epitaxially. An independent layer thickness determination and some additional structure information were obtained from Rutherford backscattering studies in combination with channeling. The spin-resolved photoemission experiments were performed for normal incidence of circularly polarized light and normal emission of the photoelectrons. The spin information allowed a separation of spin-orbit split peaks of the Ag adsorbate layer and partly also a separation of Ag adsorbate peaks from the Pt substrate background intensity. This method-induced improved resolution was used to deduce information about the development of the Ag band structure in the [Lambda]-direction from the coverage dependence of spin-resolved photoemission spectra. Dispersion of occupied bands was found to be already almost completely developed for a three-layer system. Information about the development of the band structure in its unoccupied part was obtained from the resonant behavior of peaks at about 6 eV below EF. The resonant behavior is already observed for three Ag layers and increases with layer thickness. We observe a peak in the photoemission spectra contributing to the resonances which is not predicted by existing theoretical models
Thermal stability of Ag Films with Various Interface Layers
No full textThe effects of Pd, Ni, Nb, and Ti interface layers on the thermal stability of Ag films were investigated, and those metals that are appropriate for the interface layers were summarized. The results indicated that Ti and Nb interface layers resulted in thermally stable Ag films by improving the adhesion strength of the Ag films to SiO2 substrates and by enhancing the crystal orientation of Ag(111). It was determined that appropriate interface layer metals for Ag film should have a large Gibbs free energy of formation for the oxide and an appropriate atomic diameter ratio of dmetal/dAg.journal articl
Ag-Nanoinclusion-Induced Enhanced Thermoelectric Properties of Ag<sub>2</sub>S
No full textThe effects of Ag
nanoinclusions on thermoelectric properties of
Ag2S semiconducting nanostructures, synthesized by a novel
one-pot facile polyol method, have been investigated. The resulting
products are characterized by powder XRD, EDAX, XPS, and UV–vis
techniques. FESEM images reveal the formation of disc-shaped Ag2S nanoparticles with an average thickness of 52 nm and diameters
ranging from 50 nm to a few hundreds of nm. All samples show a systematic
reduction in electrical resistivity with increasing Ag content in
the composites. The Seebeck coefficient (α) values for the Ag
nanoparticle-incorporated Ag2S nanocomposites are notably
high near 300 K because of the low-energy charge-carrier filtering
effect, which is due to preferential scattering of low-energy electrons
at the barrier potentials set up at metal–semiconductor interfaces.
The theoretical fitting of α data reveals a systematic shift
of the Fermi level toward the conduction band edge with increasing
Ag content in the composites. A significantly improved thermoelectric
power factor at 325 K is observed for a wide range of Ag nanoinclusions
with the highest ZT of 0.0029 at 325 K in the Ag2S–Ag
nanocomposite with 20.1% Ag
Krisenkommunikationskonzept der Sihlsana AG
No full textDie Sihlsana AG hat kein Krisenkommunikationskonzept mit definierten Prozessen,
Zuständigkeiten und und Hilfsmaterialien, welche für die Kommunikation in einer Krise
verwendet werden können. Somit gab die Sihlsana AG der FHNW den Auftrag,
ein Krisenkommunikationskonzept in Form einer Bachelor-Thesis zu konzipieren
AG Digitale GW
No full textDie AG Digitale Geschichtswissenschaft im Verband der Historiker und Historikerinnen Deutschlands e.V. wurde auf dem Mainzer Historikertag im September 2012 gegründet. Sie wirkt darauf hin, die Potenziale der Digital Humanities bzw. eHumanities für die Geschichtswissenschaft zu vermessen, zu nutzen und sichtbar zu machen. Dieses Blog ist das Gemeinschaftsblog der Mitglieder der AG
Ag-Ag 2 S/reduced graphene oxide hybrids used as long-wave UV radiation emitting nanocomposites
No full textWe report a facile thermal decomposition approach to synthesize Ag-Ag2S/reduced graphene oxide (Ag-Ag2S/rGO), the Ag-Ag2S nanoparticles uniformly dispersed on reduced graphene oxide with diameters of 10–20 nm. The photoluminescence spectra of Ag-Ag2S/rGO showed two obvious emission peaks at 327 and 339 nm with the excitation wavelength at 287 nm. Compared with Ag-Ag2S heterostructured clusters with two peaks at 407 and 430 nm, it showed a big blue shift and higher intensity, which makes it a novel candidate for long-wave UV radiation emitting nanocomposite.</p
Ag-Ag 2 S/reduced graphene oxide hybrids used as long-wave UV radiation emitting nanocomposites
No full textWe report a facile thermal decomposition approach to synthesize Ag-Ag2S/reduced graphene oxide (Ag-Ag2S/rGO), the Ag-Ag2S nanoparticles uniformly dispersed on reduced graphene oxide with diameters of 10–20 nm. The photoluminescence spectra of Ag-Ag2S/rGO showed two obvious emission peaks at 327 and 339 nm with the excitation wavelength at 287 nm. Compared with Ag-Ag2S heterostructured clusters with two peaks at 407 and 430 nm, it showed a big blue shift and higher intensity, which makes it a novel candidate for long-wave UV radiation emitting nanocomposite.</p
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