GeO 2 nanowires doped with Eu, Er, or Mn, as well as codoped with each of these ions and Sn, have... more GeO 2 nanowires doped with Eu, Er, or Mn, as well as codoped with each of these ions and Sn, have been grown by a catalyst-free vapor-solid process. The incorporation of Sn has been found, in all cases, to favor the formation of straight wires, which make them more appropriate for waveguiding purposes. Cathodoluminescence (CL) in the scanning electron microscope (SEM) has been used to investigate the complex light emission from the nanowires. Rare earth ion emission lines and defect related bands have been observed in Eu-and Er-doped nanowires. Optical coupling and waveguiding behavior of Er-doped GeO 2 nanowires have been demonstrated for green laser light and for Er excited luminescence in the wires. In Mn-doped GeO 2 nanowires a band centered at 1.75 eV had been detected. X-ray photoemission measurements show the presence of GeO oxide in the surface of the GeO 2 wires, which influences their native defect structure.
Sn doped GeO(2) nanowires and microwires have been grown by an evaporation-deposition method, usi... more Sn doped GeO(2) nanowires and microwires have been grown by an evaporation-deposition method, using a mixture of Ge and SnO(2) powders as precursors. Comparison with undoped GeO(2) nanowires grown by the same method shows that the presence of Sn prevents the formation of sharp bends, which makes the wires more suitable for waveguiding applications. Incorporation of about 0.5 at.% of Sn into the wires influences their morphology and gives rise to wires showing two different cross-sectional dimensions along the growth axis. Sn does not influence the luminescence spectra in the visible range but causes the appearance of emission bands in the near-infrared range. The waveguiding behavior of the Sn doped wires for green and red laser light has been demonstrated.
High aspect ratio GeO2 nano- and microwires have been grown by thermal treatment at 600 °C of com... more High aspect ratio GeO2 nano- and microwires have been grown by thermal treatment at 600 °C of compacted Ge powder under argon flow. The wires have cross-sectional dimensions from less than 100 nm to about 1 µm, depending on the duration of the treatment, and lengths of up to about 2000 µm. Waveguide behaviour of the wires was demonstrated for visible light, which shows the potential applications of these structures for optical nanodevices.
Thermal treatment of compacted GeO2 powder under argon flow leads to the growth of a dense distri... more Thermal treatment of compacted GeO2 powder under argon flow leads to the growth of a dense distribution of microwires and nanowires on the sample surface. Extended treatment causes the formation of more complex structures, including arrays of nanoneedles. Enhanced cathodoluminescence emission is associated with the wires and needles, which show a component at 2.72 eV not observed for the untreated
The development of an analytical model to predict the inelastic seismic response of reinforced co... more The development of an analytical model to predict the inelastic seismic response of reinforced concrete shear-wall buildings, including both the flexural and shear failure modes is presented. The use of shear-wall buildings is quite common in a number of seismic countries as a result of their successful seismic behavior during past severe earthquakes. The objective of this study has been to develop a computer model capable of predicting the seismic behavior of shear-wall buildings. Such model would allow better estimations to be obtained of both the ultimate lateral strength of these buildings as well as their inelastic deformation demand under severe ground motions. Such information may be used in the implementation of performance-based design procedures, and to improve present code design procedures. To fulfill this objective, a shear failure mode model based on experimental results has been added to the computer program larz. This paper discusses the most relevant problems and solutions devised during the development of this model. Validation of the model proposed to predict the inelastic seismic response of shear-wall structures was carried out by comparing its results with the actual response of two real buildings during the March 3, 1985 Chilean earthquake. In spite of the fact that the model is two-dimensional and, hence, it ignores the torsional response, the results obtained are satisfactory.
Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta... more Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta 02 tiene los netframework que deben instalarlos para que el driver de video se instale sin problemas.
Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta... more Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta 02 tiene los netframework que deben instalarlos para que el driver de video se instale sin problemas.
GeO 2 nanowires doped with Eu, Er, or Mn, as well as codoped with each of these ions and Sn, have... more GeO 2 nanowires doped with Eu, Er, or Mn, as well as codoped with each of these ions and Sn, have been grown by a catalyst-free vapor-solid process. The incorporation of Sn has been found, in all cases, to favor the formation of straight wires, which make them more appropriate for waveguiding purposes. Cathodoluminescence (CL) in the scanning electron microscope (SEM) has been used to investigate the complex light emission from the nanowires. Rare earth ion emission lines and defect related bands have been observed in Eu-and Er-doped nanowires. Optical coupling and waveguiding behavior of Er-doped GeO 2 nanowires have been demonstrated for green laser light and for Er excited luminescence in the wires. In Mn-doped GeO 2 nanowires a band centered at 1.75 eV had been detected. X-ray photoemission measurements show the presence of GeO oxide in the surface of the GeO 2 wires, which influences their native defect structure.
Sn doped GeO(2) nanowires and microwires have been grown by an evaporation-deposition method, usi... more Sn doped GeO(2) nanowires and microwires have been grown by an evaporation-deposition method, using a mixture of Ge and SnO(2) powders as precursors. Comparison with undoped GeO(2) nanowires grown by the same method shows that the presence of Sn prevents the formation of sharp bends, which makes the wires more suitable for waveguiding applications. Incorporation of about 0.5 at.% of Sn into the wires influences their morphology and gives rise to wires showing two different cross-sectional dimensions along the growth axis. Sn does not influence the luminescence spectra in the visible range but causes the appearance of emission bands in the near-infrared range. The waveguiding behavior of the Sn doped wires for green and red laser light has been demonstrated.
High aspect ratio GeO2 nano- and microwires have been grown by thermal treatment at 600 °C of com... more High aspect ratio GeO2 nano- and microwires have been grown by thermal treatment at 600 °C of compacted Ge powder under argon flow. The wires have cross-sectional dimensions from less than 100 nm to about 1 µm, depending on the duration of the treatment, and lengths of up to about 2000 µm. Waveguide behaviour of the wires was demonstrated for visible light, which shows the potential applications of these structures for optical nanodevices.
Thermal treatment of compacted GeO2 powder under argon flow leads to the growth of a dense distri... more Thermal treatment of compacted GeO2 powder under argon flow leads to the growth of a dense distribution of microwires and nanowires on the sample surface. Extended treatment causes the formation of more complex structures, including arrays of nanoneedles. Enhanced cathodoluminescence emission is associated with the wires and needles, which show a component at 2.72 eV not observed for the untreated
The development of an analytical model to predict the inelastic seismic response of reinforced co... more The development of an analytical model to predict the inelastic seismic response of reinforced concrete shear-wall buildings, including both the flexural and shear failure modes is presented. The use of shear-wall buildings is quite common in a number of seismic countries as a result of their successful seismic behavior during past severe earthquakes. The objective of this study has been to develop a computer model capable of predicting the seismic behavior of shear-wall buildings. Such model would allow better estimations to be obtained of both the ultimate lateral strength of these buildings as well as their inelastic deformation demand under severe ground motions. Such information may be used in the implementation of performance-based design procedures, and to improve present code design procedures. To fulfill this objective, a shear failure mode model based on experimental results has been added to the computer program larz. This paper discusses the most relevant problems and solutions devised during the development of this model. Validation of the model proposed to predict the inelastic seismic response of shear-wall structures was carried out by comparing its results with the actual response of two real buildings during the March 3, 1985 Chilean earthquake. In spite of the fact that the model is two-dimensional and, hence, it ignores the torsional response, the results obtained are satisfactory.
Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta... more Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta 02 tiene los netframework que deben instalarlos para que el driver de video se instale sin problemas.
Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta... more Para que todo salga perfecto, deben seguir el orden de cada carpeta en la instalación, la carpeta 02 tiene los netframework que deben instalarlos para que el driver de video se instale sin problemas.
Uploads
Papers by Pedro Hidalgo