Endocarp and pericarp extracts of Cereus fricii cactus were used to inhibit carbon steel corrosion in HCl and NaCl solutions by gravimetric assays. Extracts were mechanically obtained, concentrations were fixed and characterized by phytochemical testing and FTIR analysis, and the nature of inhibition was determined by calculation of Gibbs Free Energy. It was established that the extracts have the presence of tannins, saponins, and antioxidant compounds, which was corroborated by the FTIR analysis, showing peaks of absorbance corresponding to groups OH and COOH, with the endocarp extract presenting the highest proportion. Endocarp extracts with 5% concentration showed better performance in inhibiting corrosion than extracts obtained from epicarp, with percentages of 97.71 when inhibiting HCl and 73.91% with NaCl. The presence of tannins, saponins, and antioxidant compounds in extracts of the endocarp and epicarp favour inhibition of metal corrosion.

We report the development of a high-time resolution, 3-colour, simultaneous optical imaging system for the 2.1 m telescope in the San Pedro Mártir Observatory, México. OPTICAM will be equipped with three 2,048×2,048 pixel Andor Zyla 4.2-Plus sCMOS cameras and a set of SDSS filters allowing optical coverage in the 320–1,100 nm range. OPTICAM will nominally allow sub-second exposures. Given its instrumental design, a wide range of fast-variability astrophysical sources can be targeted with OPTICAM including X-ray binaries, pulsating white dwarfs, accreting compact objects, eclipsing binaries and exoplanets. OPTICAM observations will be proprietary for only six months and will then be made publicly available to the astronomical community.

La adsorción de Pb(II) y Ni(II) sobre cáscaras de ñame y bagazo de palma fue sistemáticamente estudiada en sistema individual y binario. Los estudios fueron realizados en sistemas batch, fijando los valores de pH y tamaño de partícula. Todas las mediciones de los metales en solución fueron hechas por absorción atómica. Se encontró que, en sistema individual, el equilibrio de adsorción siguió el modelo de Langmuir y Freundlich para ambos metales, alcanzando para las cáscaras de ñame una capacidad máxima de adsorción de 362,45 para el níquel y 68,14 mg/g para el plomo. En el caso del bagazo de palma, se estimó una capacidad de adsorción de 162,64 mg/g para el níquel y 90,28 mg/g para el plomo. En sistema binario, se observó un efecto antagónico para la acción combinada de los metales, aunque la remoción de plomo se vio significativamente incrementada en las cáscaras de ñame cuando se encontraba en solución acusa con el níquel.

In this paper we present the Medium Resolution Spectrograph ESOPO, an instrument designed and built for the 2.1m Telescope at the Observatorio Astronómico Nacional at San Pedro Mártir. We discuss the Scientific Goals and the High Level Requirements necessary to translate these goals to optical, mechanical and control specifications. We make an introduction to its conceptual dual-arm design. The optical design is based on a non-classical configuration. The gratings are illuminated in a conical mode working in a quasi Littrow configuration which has the advantage of optimizing the efficiency and the pupil area on the grating. We show here the results of an experimental evaluation of the concept. The optical design, mechanical structure, slit-mask and acquisition system, control systems, and a study of thermal compensators, are discussed briefly, references to more extended contributions in these proceedings are made. The management schematics of the project are briefly discussed.

This work presents the specifications, requirements, design, finite element analysis and results of the assembled subsystems: slit-mask, and the acquisition and guiding zone mechanisms of the ESOPO spectrograph. This spectrograph is a project of the Institute of Astronomy, National University of Mexico.

The Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) is the first light instrument for the 10.4 meters Gran Telescopio de Canarias (GTC). It's a 8.5 × 8.5 arc-min visible camera; a set of grisms provides low resolution spectroscopic capability. In this contribution the accessories and mountings for alignment are presented as well as the techniques used. Also, a complete characterization of the system at laboratory for image quality, spectral and spatial resolution, and image movement, etc. are shown.

ESOPO will be a spectrograph of medium resolution for the 2.1 m telescope of the National Observatory at San Pedro Martir, Baja California, Mexico. It has been developed by the Instituto de Astronomia of the Universidad Nacional Autonoma de Mexico (IA-UNAM). The main goal of this instrument is to modernize the capabilities of making science with that particular telescope. It is planned to achieve a spectral resolution between 500 and 5000. ESOPO is split into two arms; each one specialized in a specific wavelength range covering together all the visible light. A very important issue in spectrographs is to avoid inside thermal gradients. Different temperatures in the optical elements produce mechanical movements and image quality degradation during an exposition. The error budget analysis developed for ESOPO allows establishing the required limits for temperature gradients. In this paper is described the thermal analysis of the spectrograph, including specifications, finite element models, thermal equations and expected thermal gradients.

The structure of the spectrograph ESOPO is the stiff mount that will maintain fixed all optics elements, electronics and mechanical subsystems. The ESOPO spectrograph is a project of the "Instituto de Astronomia de la Universidad Nacional Autonoma de Mexico" (IAUNAM) to upgrade its 2.1 m telescope as a competitive facility for the next decade. The scientific purpose is to obtain a modern high efficient intermediate-low dispersion spectrograph optimized for the 3500-9000 angstrom spectral interval with a spectral resolution of 500 <= R <= 5000. It is to be used at the cassegrain f/7.5 focus of the 2.1 m telescope for general astronomical purposes. This work presents the mechanical design process and the form in which the structure was verified to comply with the ESOPO's top level image quality and stability requirements. The latter was not a lineal process. The way we resolved it is to run FEAs on the complete system and with the instrument in different operation positions during a normal cycle of observations. These results are validated through the error budget of the ESOPO. The structure is Currently under construction.

OSIRIS is the optical Day I instrument for the 10.4 m GTC telescope. OSIRIS will cover the 365 to 1000 mn spectral range, featuring an 8.6x8.6 arcmin field of view, and capabilities for direct imaging, both long-slit and multiple object spectroscopy, and fast spectrophotometry. The combination of OSIRIS wide field, tunable filters plus charge shuffling array detectors, will constitute the most powerful instrument for studying faint emission-line sources at any redshift. The present contribution gives an overview of the instrument development, currently in its verification phase before commissioning on site.

This document describes the scientific case for a wide-field 6.5-m spectroscopic telescope. The key scientific aims are linked to two different modes of operation: 1) Study the detailed astrophysics of extended systems via high-quality, medium-resolution spectroscopy using multiple Integral Field Units (IFU) and 2) Study the structure of the Universe via multiple, single-fiber spectroscopy of distant and/or compact systems. This wide-field spectroscopic facility will complement and extend present facilities, greatly enhancing the potential for new discoveries while at the same time minimizing the chances of scientific failure. Strategically we aim to address the widest possible range of astrophysically competitive areas while minimizing the number of instruments.

In March 2004 was accepted in the site of Gran Telescopio Canarias (GTC) in La Palma Island, Spain, the Commissioning Instrument (CI) for the GTC. During the GTC integration phase, the CI will be a diagnostic tool for performance verification. The CI features four operation modes-imaging, pupil imaging, Curvature Wave-front sensing (WFS), and high resolution Shack-Hartmann WFS. This instrument was built by the Instituto de Astronomia UNAM in Mexico City and the Centro de Ingenieria y Desarrollo Industrial (CIDESI) in Queretaro, Qro under a GRANTECAN contract after an international public bid. Some optical components were built by Centro de Investigaciones en Optica (CIO) in Leon Gto and the biggest mechanical parts were manufactured by Vatech in Morelia Mich. In this paper we made a general description of the CI and we relate how this instrument, build under international standards, was entirely made in Mexico.