[en] The emission spectroscopy offers the possibility of an analysis multi-element, quick, and with minimum requirements as for the preparation of the samples. These advantages are especially of great value in programs of geochemical prospecting, in which is required to know the content of several elements quickly, ignoring ahead of time many times the possible mineralization of an area. Although recently the use of sources of emission of plasma has been introduced (ICP), the equipment that use source of arch of direct current continue lending a good service the geochemical field. The development of this methodology, in the Sub bureau of Chemical Investigations of the INGEOMINAS, had its origin in the year of 1970 with the collaboration of the United States Geological Service. Taking advantage of an international agreement settled an emission spectrograph that allows to make semi-quantitative valuations of 33 metallic elements, guided mainly to samples of similar composition to the floors, rocks and tune. The purpose of this manual is to describe in detailed form, but at the same time white, the technique just as it is using at the moment, also giving data to evaluate the precision and accuracy, indicating possible interference and its diverse applications that are not limited to materials of geologic origin

[en] The effect of superposed hydrostatic pressure on the tensile deformation of particle-reinforced Al-matrix composites was analyzed using a self-consistent approximation. The composite was represented in terms of an interpenetrating network of randomly distributed spheres, which stand for the intact and damaged regions in the composite. Each sphere contained an intact or broken ceramic particle at the center, and the model assumed that the fraction of damaged spheres increased during deformation. The load partitioning between intact and damaged regions in the composite as well as the stress redistribution due to damage was computed through a self-consistent scheme. It was shown that the tensile stresses in the ceramic particles, and thus the fraction of broken particles, were reduced as the hydrostatic pressure increased. This led to a moderate improvement in the composite flow stress but more significant gains were achieved in the strain at the onset of plastic instability. Both magnitudes increased with the hydrostatic pressure until a saturation stress was reached. Particle fracture was completely inhibited at this point, and higher pressures did not have any influence on the composite behavior, which was equivalent to that of the undamaged phase in the absence of hydrostatic pressure. Using reasonable values for the matrix and reinforcement properties, the model predictions for the composite strength and strain at the onset of plastic instability were in good agreement with the experimental data in the literature for high strength Al alloys reinforced with SiC and Al₂O₃ particles

[en] ESR measurements effected on a low symmetry Cu²⁺ center in ZnO crystal irradiated with electrons at room temperature (3 MeV, 6.10¹⁸ electrons/cm²) are presented. This center exhibits the hyperfine structure characterizing an interaction with ⁶³Cu and ⁶⁵Cu nuclei

[en] Reliability analysis of hydrothermal generating systems usually includes the calculation of annual reliability indicators. This work describes a methodology to evaluate annual reliability taking into account the maintenance program of thermal units and the allocation of hydroenergy to the different subperiods of the year. The procedure takes advantage of the flexibility of hydro units to level the usual reliability indicators along the period of analysis. As an example, the analysis of the Spanish power system is presented

[en] Municipal solid waste (MSW) treatment plants have as main function the valuation of municipal waste by means of materials recovery and valuation of organic fraction. In this type of facilities, the anaerobic digestion is a biological treatment of the organic matter collected in origin or mechanically separated from the mixed MSM. The objective is its valuation under the form of biogas and organic compost. Anaerobic digestion has high energy efficiency and a good range or organic matter elimination. Nevertheless, treatment of organic matter recovered from mixed MSW presents serious operation problems due to sedimentation of heavy improper materials (sands, glasses, metals) and flotation of light materials inside the digestors and piping. (Author)

[en] In a geophysical raising of amethyst and agate was studied the possibility to apply a better suitable geophysical method. The conclusion was that the electromagnetic VLF method was suitable to identify the zones.

[en] As a result of resistance testing, Spanish NPPs are planning to install a filtered containment venting, as additional protection in severe accident management and to reduce the potential radiological emissions outside. Current filtration systems are very efficient mechanisms to minimize outside contamination, however, have a high cost. Furthermore, its implementation could condition any management strategies currently in severe accidents BWR plants.

[en] Irradiation of ZnO monocrystals with 3MeV electron creates isolated zinc vacancies and F⁺ centres. Analysis of angular variations of the ESR spectrum enabled the parameters of interaction of the F⁺ centre with a Zn⁶⁷ nucleus to be determined

[en] It is done a retrospective re-examination of 2.812 patients with abdominal symptoms, finding a global prevalence of 29.3% of colelitiasis, in reaction to 6.6 women for one man. It is pointed out the high number of young patients less than 30 years with colelitiasis (average of 21.78%), and it was also found a high prevalence in men (average 19.2%). A sample of 827 patients helped to analyse the types of colelitiasis, with 68.8% for the 1 degree, 29% for the II degree and 1.2% for the III degree. The results are compared with the reports of the other literature series and it is discussed the value of the ultrasound in relation to the non-surgical of colelitiasis treatment

[en] Corrosion of reinforcing steel can seriously limit the service life of concrete structures in marine applications. Chloride diffusion is one of the two major problems causing this phenomenon, increasing when the concrete is exposed to a marine environment in coastal areas. The service life of a structure may be divided into two general phases: an initiation period, in which the reinforcing steel surface is still passive as a result of the contact with a high pH medium the aggressive ions penetrate the concrete toward the reinforcing bar, and a propagation period that starts when the chloride ion contamination on the steel surface exceeds the critical threshold level for the passivity breakdown. The aim of this work is to examine the chloride diffusion at the initial period on a marine environment by considering the variability of the diffusion coefficients with inherent parameters of the concrete, exposed during a period of two years in Yucatan, Mexico. A model based on the second Fick's law is proposed the non-linearity of the problem is taken into account and a numerical procedure based on the finite difference methods is developed to solve the set of equations. Comparisons with experimental data are also carried out in order to show the reliability and the effectiveness of the proposed numerical model. (Author) 7 refs