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Article
Economic efficiency and targeting of the African Great Green Wall
Land degradation in the Sahel threatens livelihoods and food security. The Great Green Wall programme is a colossal initiative to restore 100 million hectares of degraded ecosystems across 11 countries in the ...
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Article
Open AccessF/OH ratio in a rare fluorine-poor blue topaz from Padre Paraíso (Minas Gerais, Brazil) to unravel topaz’s ambient of formation
Topaz [Al2SiO4(F,OH)2] is one of the main fluorine-bearing silicates occurring in environments where variably acidic (F)/aqueous (OH) fluids saturate the silicate system. In this work we fully characterized blue ...
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Article
Open AccessNeuroprotective agents in the management of glaucoma
Glaucoma is an optic neuropathy, specifically a neurodegenerative disease characterized by loss of retinal ganglion cells (RGCs) and their axons. The pathogenesis of RGC loss in glaucoma remains incompletely u...
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Article
Open AccessVertebral body compression fracture after percutaneous pedicle screw removal in a young man
Hazards and potential complications associated with pedicle screw insertions have been reported. In contrast, complications due to implant removal are rarely described. An unreported case of acute vertebral bo...
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Chapter and Conference Paper
Plasmonic Sensors for Aromatic Hydrocarbon Detection
The development of innovative materials for sensitive and selective gas sensing is a very relevant field for the current nanotechnology research. A strong effort is dedicated to the fabrication of low-cost and...
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Article
Chêneau brace for adolescent idiopathic scoliosis: long-term results. Can it prevent surgery?
The aim of this study was to evaluate the effectiveness of Chêneau brace in the management of idiopathic scoliosis.
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Article
Nanocomposites of titania and hybrid matrix with high refractive index
A sol–gel route for TiO2 nanocrystals (NCs) synthesis has been developed at low temperature without surfactants. Synthetic and processing parameters have been optimized to maximize particles’ colloidal stability ...
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Chapter and Conference Paper
One- and Two-Photon Pumped DFB Laser Based on Semiconductor Quantum Dots Embedded in a Sol-Gel Matrix
In the last years inorganic semiconductor (CdSe and CdS) quantum dots (QDs) have received great attention for their important optical properties: the design of DFB devices, based on QDs as active optical mater...
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Article
Porous sol gel silica films doped with crystalline NiO nanoparticles for gas sensing applications
A reliable sol gel route to synthesize NiO doped SiO2 films with different NiO content is here described. The films showed detectable and reversible changes in both optical and electrical properties when exposed ...
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Article
Silver-sensitized erbium-doped ion-exchanged sol–gel waveguides
Ag- and Er-doped glass films have been synthesized with a combined sol–gel and ion-exchange route. The introduction of silver as erbium sensitizer in the film was obtained by ion exchanging Er-doped SiO2–Al2O3–Na
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Article
Optical Gas Sensing Properties of Silica Film Doped with Cobalt Oxide Nanocrystals
SiO2 sol-gel films doped with cobalt oxide nanocrystals have been fabricated. The nanocrystals precipitate in the glass film at 500_°C, while the film is still porous. The nanocomposite films showed a reversible ...
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Article
Photoluminescence Spectroscopy of Er3+/Yb3+ Co-Activated Silica-Alumina Monolithic Xerogels
Two Er3+/Yb3+ monolithic silica-alumina xerogels doped with different Yb3+ concentrations were prepared by sol–gel route. The samples were thermally treated in air at 950°C for 120 h, and Raman and UV-visible-NIR...
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Article
Optical CO gas sensing using nanostructured NiO and NiO/SiO2 nanocomposites fabricated by PLD and sol–gel methods
Several kinds of NiO-based nanostructured films were prepared by pulsed-laser deposition (PLD) and sol–gel method, and CO sensing properties (1%, balanced by N2) of these films were studied. The sensitivity, defi...
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Article
Ion Beam Induced Conversion of Si-Based Polymers and Gels Layers into Ceramics Coatings
The transformations induced by ion irradiation in films of polycarbosilane and gels derived from tetraethoxysilane, methyltriethoxysilane and triethoxysilane have been studied. Hydrogen is released selectively...
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Article
NiO-SiO2 Sol-Gel Nanocomposite Films for Optical Gas Sensor
Recently nanocomposites with sensoring function are becoming a new area of interest in the field of optical gas sensor. In fact, the optical transmittance of nano-particles or thin films has been reported to b...
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Article
Nucleation of Titania Nanocrystals in Silica Titania Waveguides
SiO2(1 − x)-TiO2(x) monomode waveguides at 632.8 nm, with x in the range 0.07–0.2 and thickness of about 0.4 μm, were deposited on silica substrates by a dip-coating technique. Nucleation of TiO2 nanocrystals and...
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Article
Optical extinction resonance of Au and Ag clusters formed by ion irradiation in SiO2 and Al2O3
Three methods based on ion-beam irradiation were used to fabricate Ag and Au colloids in silica and alumina. Their surface-plasmon resonance in the visible was characterised by transmittance measurements and i...
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Article
Optical properties of silver clusters formed by ion irradiation
Precipitation of silver clusters in silica is achieved by different methods: ion implantation, ion beam mixing of superimposed layers and ion irradiation of films deposited by means of co-sputtering or sol-gel...
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Article
Fabrication of Erbium-Doped Channel Waveguides by a Combination of Ion Exchange and Sol-Gel Techniques
Erbium-doped germano-silicate thin films of good optical quality were produced by the sol-gel technique. High refractive index changes of up to 0.018 were obtained by sodium-silver ion exchange. Monomode optic...
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Article
Sol-Gel Fabrication of Rare-Earth Doped Photonic Components
The use of sol-gel to fabricate silica-on-silicon waveguides, and particularly erbium-doped waveguide amplifiers, is reviewed. In particular, efforts to use sol-gel to improve molecular homogeneity in heavily ...
