Search results for "Electronics"
showing 10 items of 4340 documents
Análisis de técnicas modernas de estimación espectral e identificación de sistemas en el estudio de ECG de superficie
1993
Desarrollo de un sistema de intercomunicación multicanal y multimedia basado en RDSI : construcción de un prototipo orientado al servicio en areas re…
2000
Stable and efficient Light-Emitting Electrochemical Cells
2014
La evolución de la tecnología exige el diseño de nuevas pantallas y sis-temas de iluminación. En este marco se necesitan rendimientos mejores y diseños avanzados y novedosos de productos. Los diodos orgánicos emisores de luz (OLEDs) son una alternativa factible a los sistemas inorgánicos debido a sus propiedades físicas únicas. Se pueden preparar dispositivos muy finos que pueden ser procesados a temperatura ambiente en sustratos grandes y flexibles. Además, sus propiedades se pueden ajustar fácilmente modificando la estructura química de las moléculas emisoras. Los rendimientos de los OLEDs están ya muy cercanos a los obtenidos utilizando las tecnologías clá-sicas inorgánicas. Sin embargo,…
Grip Strength, Neurocognition, and Social Functioning in People WithType-2 Diabetes Mellitus, Major Depressive Disorder, Bipolar Disorder, and Schizo…
2020
[Background] Frailty is a common syndrome among older adults and patients with several comorbidities. Grip strength (GS) is a representative parameter of frailty because it is a valid indicator of current and long-term physical conditions in the general population and patients with severe mental illnesses (SMIs). Physical and cognitive capacities of people with SMIs are usually impaired; however, their relationship with frailty or social functioning have not been studied to date. The current study aimed to determine if GS is a valid predictor of changes in cognitive performance and social functioning in patients with type-2 diabetes mellitus and SMIs.
Quantum well intermixing in GaInNAs/GaAs structures
2003
We report on the characteristics of quantum well intermixing in GaInNAs/GaAs structures of differing N content. Rapid thermal annealing combined with SiO2 caps deposited on the surface of the samples is used to disorder 1.3 mum GaInNAs/GaAs multiquantum wells which have been preannealed in-situ to the stage of blueshift saturation. The different effects of two capping layer deposition techniques on the interdiffusion of In-Ga have been compared, particular regarding the role of sputtering processes. The dependence of quantum well intermixing-induced photoluminescence blueshift on N concentration has provided extra information on the intrinsic properties of the GaInNAs/GaAs material system. …
Effects of rapid thermal annealing on the optical properties of low-loss 1.3μm GaInNAs∕GaAs saturable Bragg reflectors
2004
We report studies of the effect of rapid thermal annealing (RTA) on the optical properties of a low-loss 1.3 mum saturable Bragg reflector (SBR), consisting of a GaInNAs/GaAs single quantum well embedded in an AlAs/GaAs Bragg reflector grown monolithically on a GaAs substrate. RTA gives rise to a blueshift of the photoluminescence (PL) peak (and therefore of the excitonic absorption peak) and an enhancement of PL intensity, while the reflectivity properties including peak reflectivity and bandwidth are not degraded. Temperature dependent photoluminescence measurements show that the RTA-induced blueshift of photoluminescence consists of two components: one originating from the increase of op…
Corrosion and wear resistance of coatings produced on AZ31 Mg alloy by plasma electrolytic oxidation in silicate-based K2TiF6 containing solution: Ef…
2022
Abstract In this research, plasma electrolytic oxidation coatings were prepared on AZ31 Mg alloy in a silicate-based solution containing K2TiF6 using bipolar and soft sparking waveforms with 10, 20, and 30% cathodic duty cycles. The coatings displayed a net-like surface morphology consisted of irregular micro-pores, micro-cracks, fused oxide particles, and a sintered structure. Due to the incorporation of TiO2 colloidal particles and the cathodic pulse repair effect, most of the micro-pores were sealed. Long-term corrosion performance of the coatings was investigated using electrochemical impedance spectroscopy during immersion in 3.5 wt.% NaCl solution up to 14 days. The coating grown by t…
Light-induced transmission nonlinearities in gallium selenide
1999
The intensity of a He–Ne laser (633 nm, 5 mW) transmitted by different GaSe samples is observed to change in correlation with a Nd-yttrium–aluminum–garnet laser pulse (532 nm, 7.8 ns, 3 mJ) which excites them. Such time response has been attributed to a nonlinear optical effect, i.e., a decrease in the refractive index due to the exciton screening by the photogenerated carriers. A calculation of the absorption coefficient and refractive index at different carrier concentrations has led to a reconstruction of transmittance transients which fully agree with the experimental data at different incident intensities and temperatures. Chantal.Ferrer@uv.es ; Jaqueline.Bouvier@uv.es ; Miguel.Andres@…
Hybrid layers of etch-and-rinse versus self-etching adhesive systems.
2010
Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rin…
Fabrication and characterization of vacuum deposited fluorescein thin films
2011
Simple vacuum evaporation technique for deposition of dyes on various solid surfaces has been developed. The method is compatible with conventional solvent-free nanofabrication processing enabling fabrication of nanoscale optoelectronic devices. Thin films of fluorescein were deposited on glass, fluorine-tin-oxide (FTO) coated glass with and without atomically layer deposited (ALD) nanocrystalline 20 nm thick anatase TiO2 coating. Surface topology, absorption and emission spectra of the films depends on their thickness and the material of supporting substrate. On a smooth glass surface the dye initially formes islands before merging into a uniform layer after 5 to 10 monolayers. On FTO cove…