Excitation mechanisms and characterization of a multi-ionic xenon laser

The emission characteristics of an ultraviolet-visible pulsed multi-ionic xenon laser were studied through time-resolved spectroscopy and the results were interpreted using a collisional-radiative theoretical model. This analysis includes more than 20 laser lines belonging to several ionic species (Xe III-VIII). Depending on the experimental conditions, different temporal distributions of the laser lines and their corresponding spontaneous emissions can be observed. In particular, laser emission presents temporal oscillations near threshold. Pumping processes for the laser transitions have been analyzed by using this model. Relativistic Hartree-Fock calculations of laser level lifetimes and radiative transition probabilities were performed. Experimental laser gain for several transitions were obtained and compared with the theoretical values derived from the calculations

Excitation Mechanisms and Characterization of a Multi-Ionic Xenon Laser

The emission characteristics of an ultraviolet-visible pulsed multi-ionic xenon laser were studied through time-resolved spectroscopy and the results were interpreted using a collisional-radiative theoretical model. This analysis includes more than 20 laser lines belonging to several ionic species (Xe III-VIII). Depending on the experimental conditions, different temporal distributions of the laser lines and their corresponding spontaneous emissions can be observed. In particular, laser emission presents temporal oscillations near threshold. Pumping processes for the laser transitions have been analyzed by using this model. Relativistic Hartree-Fock calculations of laser level lifetimes and radiative transition probabilities were performed. Experimental laser gain for several transitions were obtained and compared with the theoretical values derived from the calculation

Plasmon properties of multilayer albumin/gold hybrid nanoparticles

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Tornado funnels passed low over Tuttle, Moore and the southern part of the city. At least 30 Oklahoma City residents were injured, mostly by flying glass and debris. Police cordoned wide section of the Capitol Hill area after the storm subsided. At Tuttle 40 homes, two cotton gins, a grade school and part of a grain elevator were damaged. The city's water supply was cut off. only minor injuries were reported.

Electrolytic ablation dose planning methodology

Electrolytic ablation (EA), a medical treatment increasingly used in solid tumor ablation, consists in the passage of a low direct electric current through two or more electrodes inserted in the tissue thus inducing pH fronts that destroys the tumor. The combined use of EA with a recently introduced one-probe two electrode device (OPTED) results in a minimally invasive tissue ablation technique. Despite its success related to low cost and minimum side effects, EA has drawbacks such as the difficulty in determining the current and time needed to assure total tumor ablation while avoiding healthy tissue intrusion. Here we introduce a realistic dose planning methodology in terms of the coulomb dosage administered and the associated pH tracking, that predicts an optimal EA/OPTED protocol treatment for a given tumor size, that is, the current and exposition time necessary to succeed in eliminating all the tumor mass while minimizing healthy tissue damage.Fil: Luján, Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Schinca, H.. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Olaiz, Nahuel Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Urquiza, S. Universidad Nacional de Mar del Plata; ArgentinaFil: Molina, Fernanda Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Turjanski, Pablo Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marshall, Guillermo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Hacia el uso sostenible del agua en la producción. Proyecto Custodia del Agua en la Cuenca del Santa Lucía.

El concepto de custodia del agua surge como una respuesta a problemas comunes en el uso responsable y sostenible del agua dulce y propone esfuerzos colectivos con origen en iniciativas individuales, voluntarias y colaborativas para gestionarla de manera sostenible

Ag nanoparticles formed by femtosecond pulse laser ablation in water: self assembled fractal structures

We report for the first time on the formation of self-assembled fractals of spherical Ag nanoparticles (Nps) fabricated by femtosecond pulse laser ablation of a solid silver target in water. Fractal structures grew both in two and three Euclidean dimensions (d). Ramified-fractal assemblies of 2 nm height and 5–14 μm large, decorated with Ag Nps of 3 nm size, were obtained in a 2d geometry when highly diluted drops of colloidal suspension were dried at a fast heating rate over a mica substrate. When less-diluted drops were dried at slow heating rate, isolated single Nps or rosette-like structures were formed. Fractal aggregates about 31 nm size in 3d geometry were observed in the as-prepared colloidal suspension. Electron diffraction and optical extinction spectroscopy (OES) analyses performed on the samples confirmed the presence of Ag and Ag2O. The analysis of the optical extinction spectrum, using the electrostatic approximation of Mie theory for small spheres, showed the existence of Ag bare core, Ag–Ag2O and air–Ag core–shell Nps, Ag–Ag2O being the most frequent type [69 % relative abundance (r.a.)]. Core-size and shell-thickness distribution was derived from OES. In situ scattering measurements of the Ag colloidal suspension, carried out by small-angle X-ray scattering, indicate a mass fractal composed of packaged 〈DSAXS〉 = (5 ± 1) nm particles and fractal dimension df = 2.5. Ex situ atomic force microscopy imaging displayed well-ramified structures, which, analyzed with box-counting method, yield a fractal dimension df = 1.67. The growing behavior of these 2d and 3d self-assembled fractals is consistent with the diffusion-limited aggregation model.Fil: Santillán, Jesica María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Fernandez Van Raap, Marcela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Física La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Mendoza Zélis, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; ArgentinaFil: Coral, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Física La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Muraca, Diego. Universidade Estadual de Campinas; BrasilFil: Schinca, Daniel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; ArgentinaFil: Scaffardi, Lucia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; Argentin

Size-Dependent Optical Properties of Metallic Nanostructures

Metallic nanostructures are a key component of current and future nanotechnology devices since their individual properties convey the appropriate characteristics for applications in several fields of science and technology. At the nanoscale size, optical properties of metal structures depend not only on the type of material but also on the dimensions and geometry of the structure, suggesting the possibility of tuning optical resonances through appropriate engineering. In this chapter, we will describe methods for calculation of size-dependent optical properties of metal nanostructures and show the successful use of extinction spectroscopy technique to determine the size of nanoparticles (Nps).Fil: Scaffardi, Lucia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Schinca, Daniel Carlos. No especifíca;Fil: Lester, Marcelo Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Videla, Fabian Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Santillán, Jesica María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Abraham, Ricardo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; Argentin