Search results for "absorption."
showing 10 items of 2682 documents
Hybrid aerosol assisted atmospheric pressure Chemical Vapour Deposition: a facile route toward nano-composite thin films?
2009
A hybrid chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nano-particles and the use of a surfactant molecule; tetraoctylammonium bromide (TOAB), is discussed. The films are fully characterised and it is shown that micro-structural changes lead to an enhancement of thermochromic properties, whilst gold nano-particles lead to a change in the films optical properties. Optical data is used in energy modelling studies to elucidate the films potential as an energy saving coating in architectural glazing.
Time-Dependent Density Functional Theory Calculations of N- and S-Doped TiO2 Nanotube for Water-Splitting Applications
2021
This research was funded by the Latvian Council of Science grant LZP-2018/2-0083. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union?s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.
Drug delivery devices based on mesoporous silicate.
2004
A mesoporous material based on aluminosilicate mixture was studied to investigate its ability to include drugs and then release them. Nonsteroidal anti-inflammatory agents such as diflunisal, naproxen, ibuprofen and its sodium salt have been used in this study. The preparation of the mesoporous material and its characterization by X-ray, N2 absorption-desorption isotherm, and thermogravimetry analysis have been described. Drug loading was performed by a soaking procedure. Drug-loaded matrices were characterized for entrapped drug amount, water absorption ability, and thermogravimetric behavior. Drug release studies also were performed at pH 1.1 and 6.8 mimicking gastrointestinal fluids. Exp…
Luminescence of impyrity and radiation defects in magnesium oxide irradiated by fast neutrons
2009
Abstract The photoluminescence, its excitation and absorption spectra of MgO single crystals are investigated before and after the irradiation with fast neutrons. It is shown that the fast neutron irradiation leads to the formation of two types of centers: the interstitial proton H + i and the Mg(OH) 2 microphase. From the behaviour of the photoluminescence (PL) and its excitation (PLE) spectra we suppose that the photoluminescence band at 730 nm of the MgO crystals belongs to the complex V − OH − Fe 3+ centers, which is transformed during the irradiation with fast neutrons. The obtained results allow assume that the transitionions play an important role in the migration of vacancies and in…
The Effect of Ni Doping on the Performance and Electronic Structure of LSCF Cathodes Used for IT-SOFCs
2018
We investigated the effect of nickel doping on the electronic structure and performance of nanostructured La0.6Sr0.4Co0.2Fe0.8-0.03Ni0.03O3-delta prepared by the one-pot sol gel method. The commercial undoped La0.6Sr0.4Co0.2Fe0.8O3-delta (ISCF0.8) was used as reference. Moreover, for comparison, Ni (3 mol %) was deposited by wetness impregnation over the La0.6Sr0.4Co0.2Fe0.8O3-delta. We show by in situ X-ray absorption spectroscopy at 900 degrees C under air flow that nickel enters the B perovskite site of the material and favors the stabilization of the cobalt oxidation state, as evidenced by the delay in the decrease of the average Co valence with respect to undoped samples. Our results a…
X-ray absorption spectroscopy studies of the off-center Ni2+ions in Ni c Mg 1-c O solid solutions
1996
In this work we present the x-ray absorption spectroscopy study of NicMg1-cO (0.01 <EQ c <EQ 1) solid solutions. The extended x-ray absorption fine structure (EXAFS) above the Ni K-edge was analyzed using the multi-shell fitting procedure. It was found that nickel ions are located in a distorted environment and shift upon dilution to the off- center positions. This fact follows from two main results: (1) in the first shell, the average Ni- O distance increases linearly upon dilution; (2) in the second shell, the average Ni-Ni distance remains unchanged and decreases slightly at low nickel concentration while the dependence of the Ni-Mg distance has a break at c approximately equals 0.6 and …
A tetranuclear organorhenium(i) complex of the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane radical anion, TCNQF4˙−
2008
The radical complex {(mu(4)-TCNQF4)[Re(CO)(3)(bpy)](4)}(PF(6))(3), as prepared and isolated from the reaction between TCNQF4 and [Re(CO)(3)(bpy)(MeOH)](PF(6)), was studied electrochemically and by IR vibrational spectroscopy, UV-Vis-NIR absorption spectroscopy, and by EPR at 9.5, 190 and 285 GHz. The isotropic g factor of 2.0058, the detectable g anisotropy, and the (185,187)Re EPR hyperfine coupling of 0.95 mT for four equivalent metal nuclei support predominant, but not exclusive, spin localisation at the bridging ligand. Nitrile and metal carbonyl stretching frequencies as well as the typically structured near infrared absorption band lend further support to (TCNQF4 (-))(Re(I))(4) as the…
Mn, Fe, Zn and As speciation in a fast-growing ferromanganese marine nodule
2004
The speciation of Mn, Fe, As and Zn in a fast-growing (0.02mm/yr), shallow-marine ferromanganese nodule has been examined by micro X-ray fluorescence, micro X-ray diffraction, and micro X-ray absorption spectroscopy. This nodule exhibits alternating Fe-rich and Mn-rich layers reflecting redox variations in water chemistry. Fe occurs as two-line ferrihydrite. The As is strictly associated with Fe and is mostly pentavalent, with an environment similar to that of As sorbed on or coprecipitated with synthetic ferrihydrite. The Mn is in the form of turbostratic birnessite with ~;10 percent trivalent manganese in the layers and probably ~;8 percent corner-sharing metal octahedra in the interlayer…
Moisture absorption, thermal conductivity and noise mitigation of clay based plasters: The influence of mineralogical and textural characteristics
2016
Abstract Three pre-mixed clay based plasters successfully employed in green building practices in several European countries (Spain, France, Germany, and United Kingdom), mainly used for interior wall coating and finishing, were tested in this paper. Their compositional and textural characteristics as well as plastic behaviour were investigated through a multi-analytical approach in a previous paper. A natural earth (Terra Rossa red soil sampled in north-western Sicily), theoretically appropriate for the production of earthen plaster, was also subjected to the same analytical routine and compared with the three commercially available products. Humidity control capacity by the determination …
2D+1 spatial solitons in heavy metal oxide glass
2007
Two-dimensional self-confinement of near-infrared picosecond pulsed beams is demonstrated in a novel heavy metal-oxide glass, three-photon absorption being the stabilization mechanism to prevent catastrophic collapse.