http://hdl.handle.net/20.500.11799/32762 2026-04-20T10:03:09Z http://hdl.handle.net/20.500.11799/32787 Electron microscopy for the evaluation of concrete surfaces modified by gamma radiation. En: Current microscopy contributions to advances in science and technology Ávila Córdoba, Liliana Ivette As we know the electron microscopy has shown its effectiveness as tool for surfaces analysis. Depending on the material is possible to describe surface features as roughness, smoothness, and so. In the case of composite materials is essential the analysis of the contributions of each component of the composite. For the case of concrete or mortar materials, some approaches have been developed and general statements are taken as standard parameters. The hydraulic concrete derived from a mixture of cement, rough and fine aggregates and water. Each one contributes on the final features of concrete, including the mechanical properties. The morphology of each component takes into account size, shape, roughness, etc. In this chapter we discuss the importance of the electron microscopy for to describe the influence of the components after mechanical testing, and some predictions can be planned for to avoid fractures. 2013-01-01T00:00:00Z http://hdl.handle.net/20.500.11799/32785 Recent developments in polymer recycling: en gamma rays: technology applications and health implications MARTINEZ BARRERA, GONZALO; Menchaca Campos, Elsa Carmina; BARRERA DIAZ, CARLOS EDUARDO; Ávila Córdoba, Liliana Ivette Gamma-rays originate from the decay of excited states of the atomic nuclei in a similar manner as the visible light originates from the decay of the atom itself. Gamma rays belong to the class of ionizing radiation, together with alpha rays (doubly ionized atoms of helium) and beta rays (electrons). The spectroscopy of gamma rays, having the unique feature that by photoeffect transform their total energy to the energy of electrons in the detection material, contributed decisively to the establishing of the decay schemes of atomic nuclei. Strong sources of gamma radiation are widely used in contemporary technologies for cancer treatment, material modification, medical imaging, and food sterilization. The main goal of this book is to present to the non-specialist reader the contemporary applications of gamma rays by selected chapters on that issue. This book has 16 selected chapters from basic application of gamma rays to applied issues like food sterilization and polymer modification. 2013-01-01T00:00:00Z http://hdl.handle.net/20.500.11799/32774 Gamma radiation as a recycling tool for waste materials used in concrete MARTINEZ BARRERA, GONZALO; Ávila Córdoba, Liliana Ivette; MARTINEZ LOPEZ, MIGUEL; HERRERA SOSA, EDUARDO SADOT; VIGUERAS SANTIAGO, ENRIQUE; BARRERA DIAZ, CARLOS EDUARDO; UREÑA NUÑEZ, FERNANDO; GONZALEZ RIVAS, NELLY MA DE LA PAZ Over the course of the last 50 years, a large number of major technological advances have contributed to the development of higher-strength, high-performance materials that provide excellent benefits. Nevertheless, in most cases, after a very short useful life, these products become waste material and contribute to environmental degra‐ dation. This situation has created an environmental crisis that has reached global proportions. In efforts to combat this issue and to promote sustainable development and reduce environmental pollution, some investigations have focused on recycling using innovative and clean technologies, such as gamma radiation, as an alternative to conventional mechanical and chemical recycling procedures. In this context, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete; for example, the compressive strength and modulus of elasticity are improved by the addition of waste particles and application of gamma radiation. In this chapter, we propose the use of gamma radiation as a method for modifying waste materials; for instance, polyethylene terephthalate plastic bottles, automotive tire rubber, and the cellulose in Tetra Pak containers, and their reuse to enhance the properties of concrete. 2015-01-01T00:00:00Z http://hdl.handle.net/20.500.11799/32770 ET de desecho y su uso en concreto en: materiales sustentables y reciclados en la construcción Ávila Córdoba, Liliana Ivette; MARTINEZ BARRERA, GONZALO; BARRERA DIAZ, CARLOS EDUARDO; UREÑA NUÑEZ, FERNANDO; LOZA YAÑEZ, JORGE ALEJANDRO El siglo XXI ha conllevado un uso casi ilimitado de los plástcos; los productos elaborados con estos materiales se encuentran presentes en la vida cotdiana formando parte de objetos como muebles, juguetes, piezas de automóvil, bolígrafos, ropa y recipientes para alimentos, solo por mencionar algunos. Sin embargo, con el desarrollo de la industria del plástco, desde hace aproximadamente 50 años, también se ha promovido indiscriminadamente el uso de envases “desechables” para transportar y contener toda clase de artculos, los que después de una muy corta vida útl, se convierten en basura, contribuyendo a deteriorar el entorno, ya que al degradarse (lo que puede suceder en tres meses o hasta en 500 años) entran en las cadenas alimentcias de animales, plantas y del mismo ser humano. Evidentemente lo anterior ha llevado a una crisis ambiental que deriva en un desarrollo poco sustentable que en la actualidad alcanza dimensiones mundiales. 2015-01-01T00:00:00Z