7,690 research outputs found

    Tendencies in Mexican-Russian economical relationship

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    In this article the questions of transformation and strengthening of the Russian-Mexican cooperation at the present stage are considered. The main products for importation and exportation of Russia and Mexico are listed for the branches of industry, agriculture, science and education. The article describes the relationship between Russia and Mexico in tourism and how it can help to improve their economic growth and country development in the next periods. The directions of development of relations in the sphere of tourism are named

    Ixodidae founded in Ostrich (Struthio camelus Linnaeus, 1766) in Portugal

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    Ostriches are acquiring a status of species for livestock production in Portugal. The introduction of this species can lead to new animal and public health problems. Ixodidae in two ostrich herds have been found following our veterinary parasitological activity. As ticks are vectors and agents of diseases, such as Crimean-Congo Haemorrhagic Fever (CCHF) we are compelled to keep epidemiological surveillance on the diseases of ostriches, in order to evaluate their implications in animal and public health

    Environmental indicators of ecological integrity and their development for running waters in northern Portugal

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    The recognition of deleterious effects of the destruction and loss of habitats (e.g. regularization of rivers, dredging, water diversion), chemical pollution, eutrophication, and climatic alterations on the aquatic organisms, as a result of human activities, combined with an urgent need of a more environmentally sensitive and ecologically sustainable management of Portuguese river systems , made us seek methods that assess the ecological condition of these systems. This article tries to make a revision of the concept of ecological integrity and the methods commonly used to assess it. Different approaches to establish the reference condition for bio-assessment are also indicated. Finally it shows the new methodologies that have been developed in Portugal for assessing the ecological condition of streams and new directions in the evaluation processes based on a better understanding of the entire aquatic ecosystem are also pointed out. An enormous challenge consists in the integration of various measurements of riverine attributes founded on key ecological processes, and in the development of more dynamic approaches that might together establish river condition and their dependence along multiple temporal and spatial scales.El reconocimiento de los efectos deletéreos de la destrucción y pérdida de hábitat (por ejemplo la regularización de ríos, el dragado o la extracción de agua), la polución química, eutrofización y alteraciones climáticas en los organismos acuáticos, como resultado de las actividades humanas, combinados con una necesidad urgente de una gestión ambientalmente más sensible y ecológicamente sustentable de los sistemas lóticos portugueses, nos incito a buscar métodos que evalúen la condición ecológica de estos sistemas. Este artículo intenta hacer una revisión del concepto de integridad ecológica y los métodos usados para evaluarlo. También son abordadas maneras diferentes de establecer la condición de referencia para la evaluación biológica. Finalmente muestra las nuevas metodologías que se han desarrollado en Portugal para evaluar la condición ecológica de los ríos y también son indicadas las nuevas direcciones en los procesos de evaluación basados en un mejor entendimiento de todo el ecosistema acuático. Un desafío enorme consiste en la integración de varias dimensiones de atributos fluviales fundamentada en los procesos ecológicos importantes y en el desarrollo de métodos más dinámicos que juntos podrán establecer la condición de los ríos y su dependencia a lo largo de múltiplas escalas temporales y espaciales

    Analysis of the IEA 2D test. 2D, 3D, steady or unsteady airflow?

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    Kinetic study of the pyrolysis of miscanthus and its acid hydrolysis residue by thermogravimetric analysis

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    The kinetic parameters of the pyrolysis of miscanthus and its acid hydrolysis residue (AHR) were determined using thermogravimetric analysis (TGA). The AHR was produced at the University of Limerick by treating miscanthus with 5 wt.% sulphuric acid at 175 °C as representative of a lignocellulosic acid hydrolysis product. For the TGA experiments, 3 to 6 g of sample, milled and sieved to a particle size below 250 μm, were placed in the TGA ceramic crucible. The experiments were carried out under non-isothermal conditions heating the samples from 50 to 900 °C at heating rates of 2.5, 5, 10, 17 and 25 °C/min. The activation energy (EA) of the decomposition process was determined from the TGA data by differential analysis (Friedman) and three isoconversional methods of integral analysis (Kissinger–Akahira–Sunose, Ozawa–Flynn–Wall, Vyazovkin). The activation energy ranged from 129 to 156 kJ/mol for miscanthus and from 200 to 376 kJ/mol for AHR increasing with increasing conversion. The reaction model was selected using the non-linear least squares method and the pre-exponential factor was calculated from the Arrhenius approximation. The results showed that the best fitting reaction model was the third order reaction for both feedstocks. The pre-exponential factor was in the range of 5.6 × 1010 to 3.9 × 10+ 13 min− 1 for miscanthus and 2.1 × 1016 to 7.7 × 1025 min− 1 for AHR

    Kinematics of a globular cluster with an extended profile: NGC5694

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    We present a study of the kinematics of the remote globular cluster NGC5694 based on GIRAFFE@VLT medium resolution spectra. A sample of 165 individual stars selected to lie on the Red Giant Branch in the cluster Color Magnitude Diagram was considered. Using radial velocity and metallicity from Calcium triplet, we were able to select 83 bona-fide cluster members. The addition of six previously known members leads to a total sample of 89 cluster giants with typical uncertainties <1.0 km/s in their radial velocity estimates. The sample covers a wide range of projected distances from the cluster center, from ~0.2 arcmin to 6.5 arcmin = 23 half-light radii (r_h). We find only very weak rotation, as typical of metal-poor globular clusters. The velocity dispersion gently declines from a central value of sigma=6.1 km/s to sigma = 2.5 km/s at ~2 arcmin = 7.1= r_h, then it remainins flat out to the next (and last) measured point of the dispersion profile, at ~4 arcmin = 14.0 r_h, at odds with the predictions of isotropic King models. We show that both isotropic single-mass non-collisional models and multi-mass anisotropic models can reproduce the observed surface brightness and velocity dispersion profiles.Comment: Accepted for publication by MNRAS. Pdflatex, 10 pages, 10 figure
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