Surface Microstructure Changes Induced by Ion Beam Irradiation

As a study result of irradiation-induced damage, various mathematical models have been developed to explain the phenomenon of irradiation-induced surface sputtering, these models are currently used in technological fields as diverse as materials characterization and in thin film deposition used in the manufacture of electronic or medical components. However, the phenomenon is not fully understood due to its high complexity, this work has the goal to present experimental evidence of the changes induced in the surface of hypereutectic alloy Ni-22% at Si promoted by the nickel ion beam irradiation, the surface changes induced will be explained in terms of the Sigmund theory of surface sputtering

Starch Biodegradable Films Produced by Electrospraying

The use of particles obtained from biopolymers is of interest in fields such as bioengineering and nanotechnology, with applications in drug encapsulation, tissue engineering, and edible biofilms. A method used to obtain these particles is electrohydrodynamic atomization (EHDA), which can generate different structures depending on the process conditions and raw materials used, opening a wide range of research in the biopolymers field, where starch is considered an excellent material to produce edible and biodegradable films. This chapter is a compilation and analysis of the newest studies of this technique, using starch with or without modifications to prepare films or membranes and their potential applications. A systematic literature review, focused on starch, and EHDA was carried out, finding 158 articles that match these criteria. From these results, a search inside them, using the words edible and biodegradable was conducted, showing 93 articles with these key words. The information was analyzed observing the preference to use corn, potato, rice, and cassava starches, obtaining mainly scaffolds and fibers and, in much less proportion, films or capsules. This review shows a window of opportunity for the study of starchy materials by EHDA to produce films, coatings, and capsules at micro or nano levels

Los β-agonistas adrenérgicos como modificadores metabólicos y su efecto en la producción, calidad e inocuidad de la carne de bovinos y ovinos: una revisión

The β-adrenergic agonists (βAA), improve animal production because they manipulate the efficiency of food use, affecting carcass characteristics and the chemical composition of meat, by reducing fat and increasing protein content. This document is a review of some aspects of the βAA mechanism of action and chemical structure, efficiency of nutrient use, growth, carcass characteristics and meat quality of ruminants under intensive feeding. Also, animal production and alimentary innocuousness are reviewed, in order to avoid the use of substances not approved in animal nutrition because they represent public health risks.Los β-agonistas adrenérgicos (βAA) se han utilizado en la producción animal, incluidos los rumiantes, propiciando una mayor eficiencia de uso del alimento, la cual se manifiesta en mejores características de la canal, así como en la composición química de la carne, al reducir el contenido de grasa y aumentar el de proteína. En el presente documento se revisa la estructura química y los mecanismos de acción de los βAA en el metabolismo de los nutrientes, así como resultados de investigaciones sobre βAA usados en la producción animal y sus efectos en la eficiencia de uso de los nutrientes que se traducen en mejoras en el crecimiento y en la calidad de la carne, principalmente en sistemas de alimentación intensiva; también se presenta información sobre la producción e inocuidad de la carne para evitar el uso de sustancias no aprobadas en la nutrición animal, por representar riesgos en la salud pública

Caracterización espectroscópica, química y morfológica y propiedades superficiales de una montmorillonita mexicana

Se describe la caracterización mediante técnicas espectroscópicas de una montmorillonita natural colectada en Cuencamé, Durango. La composición de las capas tetraédricas y octaédricas fue analizada por Resonancia Magnética Nuclear (RMN) de ángulo mágico para los núcleos de 29Si y 27Al. Las propiedades superfi ciales de la arcilla se cuantifi caron utilizando técnicas de adsorción-desorción de nitrógeno y mediante la aplicación de los métodos de Brunahuer-Emmett-Teller (BET) y Barrett-Joyner- Halenda (BJH). Los resultados indican que la arcilla analizada es una montmorillonita sódica con una capa molecular de agua adsorbida entre sus láminas, cuyos átomos de Si en la estructura de fi losilicato Q3 presentan diferente composición Si-nAl (n = 0, 1 y 2). El 3.3% de los átomos de Al correspondientes a la estructura se encuentran sustituyendo a los de Si en la capa. La presencia de los iones paramagnéticos Fe+3 y Mn+2 en la montmorillonita fue determinada por resonancia paramagnética electrónica (RPE), después de ser tratada con HCl y CF3SO3H. Adicionalmente, se discuten los resultados adquiridos por las técnicas de absorción atómica, microscopía de barrido electrónico, infrarrojo y análisis térmico gravimétrico

Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at √ s = 5.02 and 13 TeV

The pseudorapidity density of charged particles with minimum transverse momentum (pT) thresholds of 0.15, 0.5, 1, and 2 GeV/c is measured in pp collisions at the center of mass energies of √s=5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity (η) within 0.8pT larger than the corresponding threshold. In addition, measurements without pT-thresholds are performed for inelastic and nonsingle-diffractive events as well as for inelastic events with at least one charged particle having |η|2GeV/c), highlighting the importance of such measurements for tuning event generators. The new measurements agree within uncertainties with results from the ATLAS and CMS experiments obtained at √s=13TeV.