The isovector dipole strength in nuclei with extreme neutron excess

The E1 strength is systematically analyzed in very neutron-rich Sn nuclei, beyond $^{132}$Sn until $^{166}$Sn, within the Relativistic Quasiparticle Random Phase Approximation. The great neutron excess favors the appearance of a deformed ground state for $^{142-162}$Sn. The evolution of the low-lying strength in deformed nuclei is determined by the interplay of two factors, isospin asymmetry and deformation: while greater neutron excess increases the total low-lying strength, deformation hinders and spreads it. Very neutron rich deformed nuclei may not be as good candidates as stable spherical nuclei like $^{132}$Sn for the experimental study of low-lying E1 strength

Determination of the components of the gyration tensor of quartz by oblique incidence transmission two-modulator generalized ellipsometry

The two independent components of the gyration tensor of quartz, g11 and g33, have been spectroscopically measured using a transmission two-modulator generalized ellipsometer. The method is used to determine the optical activity in crystals in directions other than the optic axis, where the linear birefringence is much larger than the optical activity

Historia, epistemologia y enseñanza de las ciencias ; caso mecanica de fluidos

El documento presenta la síntesis del proyecto de investigación sobre "historia, epistemología y enseñanza de las ciencias desde una perspectiva sociocultural; un caso en mecánica de fluidos", donde a partir del análisis histórico-epistemológico de los escritos originales de Galileo, Torricelli, Pascal y Boyle se recontextualizan las experiencias y problemáticas sobre la naturaleza del vacío, el equilibrio de los líquidos y la presión atmosférica en la edad media y se muestran los aspectos relevantes para su enseñanza a nivel universitario en la formación inicial de profesores

Aflatoxin Detoxification Method Combining Mesoamerican Nixtamalization and Clay Absorption Techniques

Aflatoxins are potent carcinogens produced by fungi Aspergillus flavus and Aspergillis parasiticus. Aflatoxins are able to contaminate different crops. Once ingested in the body, aflatoxins are able to cause harmful effects such as liver cancer. Mesoamerican cultures have used the nixtamalization food process on maize since the Aztec and Mayan civilization periods. The process has proven to be effective in reducing aflatoxin concentration within maize. Extensive research has shown the effectiveness of clays, particularly the montmorillonite-rich bentonite clays, to adsorb aflatoxins. This research is aimed to combine both techniques to evaluate their synergistic effects on aflatoxin detoxification. Montmorillonite samples that have previously shown high aflatoxin adsorption capacity will be used. The aflatoxin adsorption capacity of the montmorillonite samples will be evaluated using adsorption isotherms described in Kannewischer et al., (2006) with the modification of preparing aflatoxin solutions in lime saturated water (1.5 g/L Ca(OH)2) with a very basic pH, in order to simulate the nixtamalization process. The concentration of aflatoxin left in the solution will be analyzed using the High Performance Liquid Chromatography (HPLC) method. After sampling the aflatoxin solution at different pH’s varying from alkaline, to represent nixtamalization, to acidic, the experiments proved that there is reformation of aflatoxin within stomach pHs of 2 to 3. The aflatoxin changed chemical structure once exposed to alkaline pH, causing it to open its lactone ring structure and become more solubilized in water. Due to the change in chemical structure and conversion of the nonionic species to an anionic species, which was repelled by the negatively charged montmorilloinite, the adsorption of this new structure by the clay was minimal if any, while when in acidic conditions, the aflatoxin was adsorbed well by the montmorillonite. The preliminary results implied that combining the traditional Mexican nixtamalization food process and clay incorporation in processed corn products may further limit the bioavailability of aflatoxins compared to the individual methods along

Historia, epistemologia y enseñanza de las ciencias ; caso mecanica de fluidos

El documento presenta la síntesis del proyecto de investigación sobre “historia, epistemología y enseñanza de las ciencias desde una perspectiva sociocultural; un caso en mecánica de fluidos”, donde a partir del análisis histórico-epistemológico de los escritos originales de Galileo, Torricelli, Pascal y Boyle se recontextualizan las experiencias y problemáticas sobre la naturaleza del vacío, el equilibrio de los líquidos y la presión atmosférica en la edad media y se muestran los aspectos relevantes para su enseñanza a nivel universitario en la formación inicial de profesores

Relativistic Hartree-Fock-Bogoliubov model for deformed nuclei

The relativistic Hartree-Fock-Bogoliubov model for axially deformed nuclei (RHFBz) is introduced. The model is based on an effective Lagrangian with density-dependent meson-nucleon couplings in the particle-hole channel, and the central part of the Gogny force is used in the pairing channel. The RHFBz quasiparticle equations are solved by expansion in the basis of a deformed harmonic oscillator. Illustrative RHFBz calculations are performed for carbon, neon, and magnesium isotopes. The effect of explicitly including the pion field is investigated for binding energies, deformation parameters, and charge radii and has an impact on the nuclei’s shape

Metodología para diagnosticar la gestión de la política laboral en el municipio Viñales

Aim: To design a methodology that contributes to labor managementcharacterization in the touristic municipality of Viñales, province of Pinar delRio, Cuba.Methods and techniques: The systemic method facilitated the conception ofthe methodology, depending on the elements of the executing cycle, whichmake up suitable input to identify the complex inter-sector grid thatcharacterizes performance and decision-making in the implementation of laborpolicies. Interviews and surveys were used to determine the measurementmethod. Awareness creation workshops were delivered. The analysis andsynthesis method was conducted for decomposition and relations of theoreticalaspects. Minitab 19 was used for statistical analysis.Results: The methodology was proposed to identify distinctive findings, andthe materialization of statements directed to the treatment of interests andrequirements in the working context of Viñales.Conclusions: This approach to labor policy management permitted theconfirmation of its traditional character. It shows little response to theparticularities of the municipality, and reveals the absence of integration,misuse of potentialities, and the wiil to collaborate of the private sector, whichare relevant elements to increase the development of new ways of performing,that can be adapted to the particular surrounding. Objetivo: Una metodología, cuya aplicación contribuya a caracterizar la gestión de la política laboral en el turístico municipio de Viñales, provincia Pinar del Río, Cuba. Métodos y técnicas: El método sistémico propició la concepción de la metodología a partir de los elementos del ciclo directivo que constituyen un insumo competente para identificar el complejo entramado interactoral que caracteriza el desempeño y la toma de decisiones en la implementación de la política laboral. En la delimitación del método de medición se usaron las entrevistas y encuestas como fuentes de información. Se desarrollaron talleres de sensibilización. Los procedimientos de análisis y síntesis se aplicaron en la descomposición y relación de los aspectos teóricos. Se empleó el software estadístico Minitab versión 19. Los procedimientos de análisis y síntesis se aplicaron en la descomposición y relación de los aspectos teóricos. Resultados: La propuesta de una metodología para el levantamiento de los hallazgos representativos y la concreción de planteamientos dirigidos al tratamiento de intereses y demandas en el contexto laboral del municipio de Viñales.  Conclusiones: El acercamiento a la gestión de la política laboral permitió comprobar su carácter tradicional; denota la poca respuesta a las particularidades del municipio y revela la falta de integración y desaprovechamiento de las potencialidades y disposición de colaboración del sector privado, elementos relevantes para impulsar el desarrollo de nuevas formas de hacer contextualizadas al medio.&nbsp