Time filter

Source Type

Williams T.,Institute Ecologia AC | Rodriguez-Del-Bosque L.A.,Instituto Nacional de Investigaciones Nucleares
Annual Review of Entomology | Year: 2013

Mexico is a megadiverse country that forms part of the Mesoamerican biological corridor that connects North and South America. Mexico's biogeographical situation places it at risk from invasive exotic insect pests that enter from the United States, Central America, or the Caribbean. In this review we analyze the factors that contributed to some highly successful past programs involving classical biological control and/or the sterile insect technique (SIT). The present situation is then examined with reference to biological control, including SIT programs, targeted at seven major pests, with varying degrees of success. Finally, we analyze the current threats facing Mexico's agriculture industry from invasive pests that have recently entered the country or are about to do so. We conclude that despite a number of shortcomings, Mexico is better set to develop biological control-based pest control programs, particularly on an area-wide basis, than many other Latin American countries are. Classical and augmentative biological control and SIT-based programs are likely to provide effective and sustainable options for control of native and exotic pests, particularly when integrated into technology packages that meet farmers' needs across the great diversity of production systems in Mexico. © 2013 by Annual Reviews. All rights reserved.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP.2010.1.2-4 | Award Amount: 5.34M | Year: 2010

The aim of the present project is to explore the properties and possible applications of bismuth and bismuth based compounds when they are synthesized at the nanometric scale. This approach is motivated by the uncommon but advantageous properties of bismuth which, in part, have been exploited for many years. However, there are many unexplored possibilities and with the advent of nanotechnology new prospectives may be expected. We believe this approach will lead to new and high-tech applications of bismuth based materials, adding new value to one of the major mining products of Mexico (second most important world production) and boost the related economic benefits which at present are low. In the project, we have integrated complementary research groups from Mexico and Europe covering interdisciplinary fields. In the thematic work-packages, research groups working on the synthesis of the nanostructured materials will collaborate with others doing the physical-chemical materials characterization and the application development. The materials include Bi, Bi2O3 and Bi2S3 nanostructures, Bismuth metal oxide nanostructured ceramics and thin films, bismuth-based nanocomposites where Bi constitutes the nanoscale inclusion and the matrices varied from ceramics, polymers or glasses, and finally Bi superconductors. Extensive chemical and structural characterization will be required to correlate the synthesis parameters with the physical properties. Finally, the project includes the physical evaluation focused on the optical, electrical, magnetic, ferroelectric, etc. properties, according to the proposed applications. The time scale of the project is sufficient for the preparation of masters degree students and the initial years of doctorate students. These students will work in a very academic-rich environment and at the same time have contact with the industrial partners in the project, some of which are leaders in the development of Bi-based commercial products.

Aguilera E.F.,Instituto Nacional de Investigaciones Nucleares | Kolata J.J.,University of Notre Dame
Physical Review C - Nuclear Physics | Year: 2012

Recent experimental results for the fusion of the proton-halo system 8B+58Ni are discussed. A strong enhancement is observed both below and above the barrier. This is qualitatively different from the usual sub-barrier enhancement observed for many heavy-ion systems. Arguments are given that relate the enhancement to a static halo effect directly associated to the extended size of the proton-halo state. A simple single-barrier model is proposed which describes the fusion cross sections in terms of a maximum angular momentum for fusion, L f. It is shown that a linear energy dependence for L f gives a surprisingly good description of the experimental fusion excitation function not only for 8B+58Ni but also for the neutron-halo systems 6He+ (209Bi,64Zn). The model is also applied to several weakly bound systems. © 2012 American Physical Society.

Instituto Nacional Of Neurologia Y Neurocirugia Manuel Velasco Suarez, Instituto Mexicano Del Seguro Social and Instituto Nacional de Investigaciones Nucleares | Date: 2010-03-17

The purpose of the present invention is to demonstrate that semiconducting and non-biodegradable implants made with polypyrrole and polyethylenglycol copolymers and iodine-doped and plasma-synthesised pyrrole polymers, have a neuroprotector effect and induce the reconnection of the spinal cord after an injury; this effect was proved in a model involving a complete section of the spinal cord in rats; the results o the functional evaluation demonstrated 5 times greater recovery in animals implanted with the polypyrrole-polyethylenglycol copolymer compared with the control group which only underwent a complete section of the spinal cord; in addition, the functional recovery of the group with iodine-doped polypyrrole was ten times greater compared to the control group; in the histological study various inflammatory and immune cells were identified at the injury site in the three experimental groups with and without implants and the integration of the polymers in the nervous tissue of the spinal cord was also observed; finally, no respiratory, renal or skin infections, adverse effects or rejection of the biomaterials were found in any of the animals.

Research Center En Quimica Aplicada, Instituto Nacional de Investigaciones Nucleares and Research Center Cientifica Of Yucatan | Date: 2013-07-03

A method for obtaining sweet gas, synthetic gas, and sulphur from natural gas. The method includes the steps of removing impurities from the natural gas for obtaining pre-treated natural gas; sweetening the pre-treated natural gas through a separation using a plurality of membranes for obtaining sweet gas and acid gases; ionizing the acid gases to dissociate them into sulphur and synthetic gas with remnants of acid gases; and neutralizing the synthetic gas with remnants of acid gases for generating sweet gas. Likewise, a system is presented on how to implement the method.

Aviles A.,National Autonomous University of Mexico | Cervantes-Cota J.L.,Instituto Nacional de Investigaciones Nucleares
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

We study some properties of the dark degeneracy, which is the fact that what we measure in gravitational experiments is the energy-momentum tensor of the total dark sector, and any split into components (as in dark matter and dark energy) is arbitrary. In fact, just one dark fluid is necessary to obtain exactly the same cosmological and astrophysical phenomenology as the ΛCDM model. We work explicitly the first-order perturbation theory and show that beyond the linear order the dark degeneracy is preserved under some general assumptions. Then we construct the dark fluid from a collection of interacting fluids. Finally, we try to break the degeneracy with a general class of couplings to baryonic matter. Nonetheless, we show that these interactions can also be understood in the context of the ΛCDM model as between dark matter and baryons. For this last investigation we choose two independent parametrizations for the interactions, one inspired by electromagnetism and the other by chameleon theories. Then, we constrain them with a joint analysis of CMB and supernovae observational data. © 2011 American Physical Society.

Cabral-Prieto A.,Instituto Nacional de Investigaciones Nucleares
Hyperfine Interactions | Year: 2014

Simulated and experimental broadened Mössbauer spectra are analyzed using several distribution functions. The resolution Hesse and Rübartsch data are reproduced in order to analyze the origin of the oscillations appearing in the recovered distribution function. The lined triangular distribution is used and some of its properties are described. The no implicit nth-nomial distribution function P(x)=(aCos (πx) + bSin (πx))n is introduced, complementing the Window and Hesse and Rübartasch no implicit distribution functions. This new no implicit distribution function gives similar results of those of Window's method. In addition, the Window method has also been modified by inserting a smoothing factor λC. For 0<λC < 1 a hyperfine distribution with low resolution may be obtained; for λC > 1, the opposite is obtained. The Levenberg-Marquardt algorithm is used to solve the involved Fredholm integral equation rather than the typical second order regularized algorithm. From the extracted hyperfine field distribution functions of the Mössbauer spectra of the amorphous and crystallized Fe70Cr2Si5B16 magnetic alloy the short range atomic order for the amorphous state of this alloy can be inferred. © 2013 Springer Science+Business Media Dordrecht.

Aguilera E.F.,Instituto Nacional de Investigaciones Nucleares
Journal of Physics: Conference Series | Year: 2012

Recent results for total reaction and fusion excitation functions for halo systems are compiled. The striking similarity in the behavior of total cross sections for proton-halo ( 8B) and neutron-halo ( 6He) systems is pointed out. Static and dynamic halo effects are elucidated by comparing data for a neutron-halo nucleus and its core. Fusion cross sections are discussed in terms of a maximum angular momentum for fusion, L f. A linear energy dependence for L f is consistent with the data for all the existing measurements so this might actually be a characteristic feature of true halo systems. A qualitative difference between the fusion of neutro-halo and proton-halo systems also is pointed out. © Published under licence by IOP Publishing Ltd.

Jimenez-Reyes M.,Instituto Nacional de Investigaciones Nucleares | Solache-Rios M.,Instituto Nacional de Investigaciones Nucleares
Journal of Hazardous Materials | Year: 2010

The effects of pH, contact time, fluoride-ion concentration, and the dose of sorbent on the sorption of fluoride ions by hydroxyapatite were studied. Equilibrium was reached in 16h of contact time and the maximum sorption of fluoride ions was in the pHeq range between 5 and 7.3. The highest efficiency in the sorption system was determined by using 0.01g of hydroxyapatite and 25mL of solution. The pseudo-second order model described the kinetic sorption processes, and the Freundlich model, the sorption isotherm process. These results indicated that the mechanism was chemisorption on a heterogeneous material. Fluoride ions were partially desorbed using an alkaline solution. © 2010 Elsevier B.V.

Instituto Nacional de Investigaciones Nucleares | Date: 2011-10-14

The invention relates to a method and furnace allowing the use of filter earth (diatomaceous earth) waste, in which the organic material is removed using the method of the application. The furnace comprises a container in which the industrial waste is deposited, and a folding table is used to transport the material. The invention also includes an agitator with a base, used to lower blades and remove the treated material. The gases generated are collected by an extractor which includes a cooling jacket and are subsequently sent to an absorber system in which they are neutralised. Said device and method are used to obtain lightweight materials with low porosity and high compression strength, rendering solid granular industrial waste that is dangerous to the environment suitable for use in the construction or mechanical industries.

Loading Instituto Nacional de Investigaciones Nucleares collaborators
Loading Instituto Nacional de Investigaciones Nucleares collaborators