Search results for "Metals"
showing 10 items of 2013 documents
Solution-processible electrode materials for a heat-sensitive piezoelectric thin-film sensor
2012
Abstract Piezoelectric sensors are needed in a wide range of applications from physiological measurement applications to industrial monitoring systems. Custom-designed, highly integratable and cost-effective sensor elements can be manufactured by using flexible materials in combination with high-throughput printing for fabrication. This would also enable the embedding of ubiquitous sensors in our living environment to improve the common welfare. Here, we have fabricated flexible piezoelectric sensor elements using printing methods. We demonstrated that alternative, printable electrode materials are compatible with temperature-sensitive functional substrates. Low-temperature curable electrod…
Controlling phase formation in solids: rational synthesis of phase separated Co@Fe2O3 heteroparticles and CoFe2O4 nanoparticles
2011
A wet chemical approach from organometallic reactants allowed the targeted synthesis of Co@Fe(2)O(3) heterodimer and CoFe(2)O(4) ferrite nanoparticles. They display magnetic properties that are useful for magnetic MRI detection.
Tunable coaxial cavity resonator for linear and nonlinear microwave characterization of superconducting wires
2011
We discuss experimental results obtained using a tunable cylindrical coaxial cavity constituted by an outer Cu cylinder and an inner Pb-BSCCO wire. We have used this device for investigating the microwave response of the superconducting wire, both in the linear and nonlinear regimes. In particular, by tuning the different modes of the cavity to make them resonant at exactly harmonic frequencies, we have detected the power emitted by the superconducting inner wire at the second- and third-harmonic frequency of the driving field. The results obtained in the nonlinear regime, whether for the microwave surface impedance or the harmonic emission, are qualitatively accounted for considering inter…
Fluoreno[2,1-a]fluorene: an ortho-naphthoquinodimethane-based system with partial diradical character.
2019
Fluoreno[2,1-a]fluorene, a molecule comprising fused ortho-quinodimethane units in a 1,5-napthoquinodimethane core, has been prepared and investigated with spectroscopy (UV-Vis-NIR, 1H-NMR and Raman), SQUID magnetometry, spectroelectrochemistry and quantum chemistry. While para-quinodimethanes with a 2,6-substitution pattern exist as closed-shell species and meta-quinodimethanes with 2,7-substitution favour a ground electronic state with very large diradical character, our 1,5-substituted ortho-naphthoquinodimethane-based system exhibits an intermediate degree of diradical character.
Forming of aluminum foam sandwich panels: Numerical simulations and experimental tests
2006
Abstract The forming of the completed aluminium foam sandwich (AFS) panels would determine an improvement in the manufacturing of parts and panels. In this paper the authors have investigated the formability of AFS through experiments and numerical simulations. As far as the former are concerned, commercially prepared panels have been considered and bending and stamping processes have been taken into account. In addition, FEM analyses have been developed, utilizing a porous material model following the evolution of the material density throughout the forming processes.
Layered gadolinium hydroxides for low-temperature magnetic cooling
2015
Layered gadolinium hydroxides have revealed to be excellent candidates for cryogenic magnetic refrigeration. These materials behave as pure 2D magnetic systems with a Heisenberg-Ising critical crossover, induced by dipolar interactions. This 2D character and the possibility offered by these materials to be delaminated open the possibility of rapid heat dissipation upon substrate deposition.
Survival and differentiation of embryonic neural explants on different biomaterials
2006
Biomaterials prepared from polyacrylamide, ethyl acrylate (EA), and hydroxyethyl acrylate (HEA) in various blend ratios, methyl acrylate and chitosan, were tested in vitro as culture substrates and compared for their ability to be colonized by the cells migrating from embryonic brain explants. Neural explants were isolated from proliferative areas of the medial ganglionic eminence and the cortical ventricular zone of embryonic rat brains and cultured in vitro on the different biomaterials. Chitosan, poly(methyl acrylate), and the 50% wt copolymer of EA and HEA were the most suitable substrates to promote cell attachment and differentiation of the neural cells among those tested. Immunofluor…
Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4
2019
The authors wish to express gratitude to K. Smits for TEM measurements. This research is funded by the Latvian Council of Science, project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1-0335. GK wishes to expresses gratitude to Arnis Riekstins "MikroTik" donation. Donations are administered by the University of Latvia Foundation. © 2019. This work is licensed under a CC BY-NC-ND 4.0 license.
Evidence of hexagonal WO3 structure stabilization on mica substrate
2009
International audience; WO3 nanorods are grown by a simple vapor deposition method on a mica substrate and characterized by Selected Area Electron Diffraction and Energy Dispersive X-rays Spectroscopy. Experimental results show the clear evidence of an unexpected WO3 hexagonal structure as well as an epitaxial growth on the mica substrate. Besides, potassium is evidenced inside the nanorods. It is thus deduced that a metastable WO3 hexagonal phase is stabilized by epitaxy through a tungsten bronze interlayer having same hexagonal structure.
A critical approach to the toxic metal ion removal by hazelnut and almond shells
2018
The adsorption capacity of ground hazelnut (HS) and almond (AS) shells towards Pb(II) and Cd(II) has been studied at pH = 5, in NaNO3 and NaCl ionic media, in the ionic strength range 0.05-0.5 mol L-1. Kinetic and equilibrium experiments were carried out by using the Differential Pulse Anodic Stripping Voltammetry technique to check the amount of the metal ion removed by HS and AS materials. Different kinetic and equilibrium equations were used to fit experimental data and a statistical study was done to establish the suitable model for the data fitting. A speciation study of the metal ions in solution was also done in order to evaluate the influence of the ionic medium on the adsorption pr…