By collecting optical and infrared photometry, as well as medium resolution spectroscopy, we have discovered a sample of low mass stars and brwon dwarfs in the young cluster IC2391. Using the lithium depletion boundary near the substellar limit, we have estimated the age of the cluster as ∼50 Myr. We have also estudied the Hα emission in this sample.

In this review, we introduce a variety of surface sensitive techniques for the study of organic thin films, and applications to organic devices. These studies include surface plasmon emission light, organic thin film transistors, combination of quartz crystal microbalance and optical waveguide spectroscopy, evaluation of alignment of liquid crystal molecules at surfaces, and biosensor applicati...

We have studied by electrical and optical methods the properties of the defects to possibly identify which ones affect the luminescence of the material. We have characterized Er-doped Si samples grown by the Liquid Phase Epitaxy (LPE) method, a relatively simple and inexpensive technique, by means of photoluminescence (PL), cathodoluminescence, EXAFS and deep level transient spectroscopy. The o...

this work describes the optical and structure properties of nickel sulfide and cobalt sulfide nanoparticles in zsm-5 zeolite. the samples were obtained by sulfidation of the ni2+ and co2+ ion-exchange zsm-5 zeolites in a na2s solution at room temperature. the optical properties of the samples were studied by uv-visible spectroscopy. their crystalline structure and morphology were studied by x-r...

The influence of graphene and retinoic acid (RA) - a π-conjugated organic semiconductor - interface on their hybrid system is investigated. The physical properties of the interface are assessed via scanning probe microscopy, optical spectroscopy (photoluminescence and Raman) and ab initio calculations. The graphene/RA interaction induces the formation of a well-organized π-conjugated self-assem...

As part of our multiwavelength campaign of observations of GX 339–4 in 1996 we present our Keck spectroscopy performed on May 12 UT. At this time, neither the ASM on the Rossi X-Ray Timing Explorer nor BATSE on the Compton Gamma-Ray Observatory detected the source. The optical emission was still dominated by the accretion disk with V ≈ 17 mag. The dominant emission line is Hα, and for the first...

Abstract:Nanostructured titania was synthesized by colloidal and polymeric sol-gel routes. Stable colloidal and polymeric titania sols were prepared by adjusting the proper values of the acid/alkoxide and the water/alkoxide molar ratios. The properties of sols were determined by dynamic light scattering technique and synthesized titania was characterized by thermogravimetry and differential the...