Search results for "rfa"
showing 10 items of 11106 documents
Deep-learning based reconstruction of the shower maximum X max using the water-Cherenkov detectors of the Pierre Auger Observatory
2021
The atmospheric depth of the air shower maximum $X_{\mathrm{max}}$ is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of $X_{\mathrm{max}}$ are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of $X_{\mathrm{max}}$ from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of $X_{\mathrm{max}}$. The reconstruction relies on the signals induced by shower particles in the groun…
Visible luminescence of nanosilica: slow and fast contributions
2010
Bright blue emission of synthesized silica nanoparticles conferred by surface defects
2013
Temperature-responsive hybrid nanomaterials based on modified halloysite nanotubes uploaded with silver nanoparticles
2022
New temperature-responsive hybrid nanomaterials based on modified halloysite nanotubes (HNTs) containing grafted polymer brushes with silver nanoparticles have been successfully fabricated. We used a three steps process including synthesis of the initiating coatings onto HNTs surface, fabrication of the POEGMA – poly(oligo(ethylene glycol)ethyl ether methacrylate) grafted brushes and synthesis of the silver nanoparticles (AgNPs). The synthesis and properties of hybrid nanomaterials were studied by FT-IR, TGA and DLS methods. It is shown that the introduction of AgNPs, formed from 0.005 M AgNO3 solution leads to a significant reduction of low critical solution temperature (LCST) of the polym…
Localized surface plasmon resonance in silver nanoparticles: Atomistic first-principles time-dependent density-functional theory calculations
2015
We observe using ab initio methods that localized surface plasmon resonances in icosahedral silver nanoparticles enter the asymptotic region already between diameters of 1 and 2 nm, converging close to the classical quasistatic limit around 3.4 eV. We base the observation on time-dependent density-functional theory simulations of the icosahedral silver clusters Ag$_{55}$ (1.06 nm), Ag$_{147}$ (1.60 nm), Ag$_{309}$ (2.14 nm), and Ag$_{561}$ (2.68 nm). The simulation method combines the adiabatic GLLB-SC exchange-correlation functional with real time propagation in an atomic orbital basis set using the projector-augmented wave method. The method has been implemented for the electron structure…
Pulicaria glutinosa Extract: A Toolbox to Synthesize Highly Reduced Graphene Oxide-Silver Nanocomposites
2015
A green, one-step approach for the preparation of graphene/Ag nanocomposites (PE-HRG-Ag) via simultaneous reduction of both graphene oxide (GRO) and silver ions using Pulicaria glutinosa plant extract (PE) as reducing agent is reported. The plant extract functionalizes the surfaces of highly reduced graphene oxide (HRG) which helps in conjugating the Ag NPs to HRG. Increasing amounts of Ag precursor enhanced the density of Ag nanoparticles (NPs) on HRG. The preparation of PE-HRG-Ag nanocomposite is monitored by using ultraviolet-visible (UV-Vis) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The as-prepared PE-HRG-Ag nanocomposities display excellent surfac…
La pizarra digital en los alumnos con Síndrome de Marfan. Un caso de apoyo de las TIC en la atención a la diversidad
2010
En el marco en los niveles de enseñanza no universitaria cada vez es más amplia la presencia de todo tipo de tecnologías informáticas; estas herramientas intentan ofrecer respuesta a alguna de las muchas necesidades educativas especiales que presentan los alumnos. En ese sentido, presentamos ciertas características de la conocida pizarra digital que la hacen especialmente interesante en los alumnos afectados por el Síndrome de Marfan. En el ámbito de la escuela inclusiva señalamos que la pizarra digital se convierte en un elemento facilitador del proceso de enseñanza y aprendizaje de unos alumnos que, debido a sus discapacidades, se encuentran en situación desfavorecida respecto al resto de…
Multiple point spaces of finite holomorphic maps
2016
Esta tesis trata sobre espacios múltiples de aplicaciones holomorfas finitas entre variedades complejas. Nuestro enfoque es el de la teoría de singularidades, y las aplicaciones serán consideradas bajo la relación de A-equivalencia, es decir, salvo cambios de coordenadas en partida y llegada. Nos centramos en relacionar propiedades de los espacios de puntos múltiples con propiedades como la A-estabilidad y la A-determinación finita. En generaEl trabajo está organizado de la siguiente manera: El Capítulo 1 contiene los fundamentos básicos necesarios para el resto del trabajo. En el Capítulo 2 definimos los espacios de puntos múltiples de una aplicación. Demostramos que solo hay una manera de…
Maturation of Epidermal Langerhans Cells In Vitro Is Accompanied by Downregulation of 4F2 (CD98) as Determined by Differential Display
1998
Following short-term culture, Langerhans cells mature morphologically and functionally into potent immunostimulatory cells. As regulation of gene expression accompanies this maturation process, it is likely that differentially expressed genes are involved in the maturation events. Using the recently described method of differential display, we generated cDNA expression patterns starting with mRNA of murine epidermal Langerhans cells isolated either directly (fLC) or following 3 d cultivation (cLC). Five hundred putative differentially expressed cDNA fragments were recovered from the gel. For a part of the fragments differential expression was confirmed by dot blot and Southern hybridization…
A fluorescence study of the loading and time stability of doxorubicin in sodium cholate/PEO-PPO-PEO triblock copolymer mixed micelles
2019
Abstract Hypothesis Doxorubicin hydrochloride (DX) is one of the most powerful anticancer agents though its clinical use is impaired by severe undesired side effects. DX encapsulation in nanocarrier systems has been introduced as a mean to reduce its toxicity. Micelles of the nonionic triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) (PEO-PPO-PEO), are very promising carrier systems. The positive charge of DX confines the drug to the hydrophilic corona region of the micelles. The use of mixed micelles of PEO-PPO-PEO copolymers and a negatively charged bile salt should favour the solubilization of DX in the apolar core region of the micelles. Experiments We st…