Results 1 - 10 of 38
Results 1 - 10 of 38. Search took: 0.016 seconds
|Sort by: date | relevance|
[en] Full text: Mexico has a Nuclear Power Plant located at Laguna Verde Veracruz. It has two General Electric BWR reactors of 680 MWe each, The first reactor started operating in 1990 and the second one in 1995. Nuclear power contributes about 4.4 % of the total electricity produced in Mexico. The Mexican regulatory body has given the two reactors an operation license of 30 years. The Laguna Verde Nuclear Plant was uprated to 5% of its nominal capacity in 1999 and at the moment there is an ongoing project to uprate it to 20%, this however, implies changing major components such as the turbines. At the present time there are not government official plans to built new NPPs in Mexico; however studies about de technical and economical feasibility new nuclear capacity are being carried out by the CFE and the Mexican Nuclear Research Institute. In Mexico the production of nuclear power is reserved to the state trough Federal Electricity Commission (CFE). The Program of Works and Investment of the Electrical Sector (POISE) is an annual national electricity program prepared by CFE taking into account the electricity needs for the following 10 years. The Mexican government has stated in the POISE 2009-2018 plans to install close to 18,000 MWe by the year 2018 of new electricity capacity, of this amount 15,500 MWe will be produced using conventional sources and 2,500 MWe will be defined in the future considering technologies that can include nuclear power. The most viable option to increase nuclear capacity in Mexico besides the current reactors uprate program is to build new reactors in the same site of Laguna Verde. This site was originally planed to house up to 4 reactors. Another very important issue is the operational license extension to at least 60 years, this can only be archived through a life extension program which is currently underway. The Mexican Nuclear Research Institute has been carrying out a materials surveillance program to determine the current state of the reactor vessel as well as the internals and cables, the results of this program will be the basis for a license extension from the regulatory commission. It is necessary to carry out a more thorough investigation on the cost of nuclear power, specially in the current world economic crisis where there are huge variations in costs an great uncertainties in the estimation of future energy costs. Mexico's oil production is on the decline and is necessary to find alternative energy sources to secure a bigger energy independence through economical and environmentally friendly options. (author)
[en] In the present work, the influence of Fe/As ratio on the As removal, from aqueous solutions, applying flotation by colloidal adsorption was studied. Ferric chloride was used as coagulant and dodec il sulfate as collector, and arsenic trioxide was utilized to preparing the solutions. The obtained results show that the highest arsenic removal was accomplished in the range of pH between 4 and 5,5, and the increasing of the initial concentration of Fe(III), increases the removal of arsenic from the solution. However, with the decreasing of the initial concentration of arsenic in the solution, it is required a larger Fe/As ratio for its removal. For solutions containing: 13,73, 1,71 and 0,105 mg/L of arsenic, it was shown that to remove around 95% of the dissolved arsenic, a Fe/As ratios of approximately 6/1, 18/1 and 800/1, respectively, are required. (Author) 31 refs
[en] Regardless of the advances in simulation power of computers and material constitutive models, there is an agreement with the need of structural experimental testing. In particular, great effort has been made to understand the performance of structures under exceptional loads such as earthquakes or impacts. Several methods have been used in structural testing: quasi-static testing, shake tables and hybrid simulation. In the latter, only some parts of the structure are experimentally tested, whereas the others are numerically simulated. Test progresses as the results of the physical test are fed into the model and its outputs are imposed on the physical substructure. In this work, a review of these methods is presented comparing their strengths, weaknesses and areas of application. Emphasis is put on hybrid simulation and application possibilities to areas different than Seismic Engineering are suggested; for instance: testing of vibration damping devices under crowd induced forces or problems such as fluid or vehicle-structure interaction.
[en] The LHCb physics programme is now underway. The data collected in 2009 and in the first period of the 2010 run have allowed for a range of interesting minimum bias physics measurements, including those of prompt Ks0, Lambda, anti-Lambda, proton and anti-proton production. Heavy flavour signals have also been collected and detailed studies of J/ψ production, both prompt and from B-decays, are underway. The status of these measurements will be reviewed, and the prospects will be given for the core LHCb CP-violation and rare decay programme in the remainder of the 2010-11 run.
[en] 'Full text:' The main sources of electricity generation in Mexico are fossil fuels, mainly gas. At the end of 2013, nearly 50% of total electricity generated in Mexico, was generated by gas and 12% using coal. The Mexican 2012-2026 National Strategy for Energy (ENE-2012) proposes a diversification of generating sources in the electricity sector. Also states an objective indicating that by 2026, at least 35% of the total electricity produced should be by means of non-fossil fuels. Currently, Mexico has one nuclear power plant (Laguna Verde) consisting of two BWR units, with a combined capacity of de 1,610 MW. This power represents 3.08% as total installed capacity in the country, and represents 4.6% of the country's generated electrical energy on 2013. This work analyzes ENE-2012, considering different scenarios for nuclear energy in order to comply with the participation of clean energy sources by 2026. From this analysis we can conclude that nuclear energy should have more participation in the Mexican electricity generation mix for the near future. (author)
[en] A combination of Moessbauer spectroscopy (CEMS and transmission) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX) was employed to study the differences between coat and body in Campanian and Terra Sigillata wares. Conclusions about type of clay, origin of colour, and fabric and firing technology are established. (orig.)
[en] A kinetic CEMS study of the early corrosion stages of iron and weathering steel in low (LAC) and very low (VLAC) SO2-polluted atmospheres has been carried out. The morphology and sulphur content of corrosion products were examined with SEM-EDAX. (orig.)
[en] This section presents some of the results of four studies on international public opinion about nuclear energy, the first one made several years before the Fukushima accident, conducted in 2005 by the IAEA through the company Globe Scan Inc. The second study was conducted by the same company in 2011 a few months after the Fukushima accident, including also corresponding results to two studies conducted by the British firm Ipsos Mori (of years 2011 and 2012 respectively). Finally three studies conducted by the Instituto Nacional de Investigaciones Nucleares (ININ) in 2006, 2008 and 2013 are presented. From the results of these studies was determined that the Fukushima accident itself had a negative effect on public opinion in Mexico, as throughout the world, but this trend is reversing. Also it found that public opinion in Mexico on using reactors to generate electricity is favorable, although not still has much support from the government for the construction of new nuclear power plants. (Author)