Conversaciones de Ulloa con sus tres hijos en el servicio de la Marina

El autor divide los conocimientos adquiridos a lo largo de los años dedicado a la marina en forma de conversaciones con sus hijos.269 págs

Stacked GaAs(Sb)(N)-capped InAs/GaAs quantum dots for enhanced solar cell efficiency

Different approaches have arisen aiming to exceed the Shockley-Queisser efficiency limit of solar cells. Particularly, stacking QD layers allows exploiting their unique properties, not only for intermediate-band solar cells or multiple exciton generation, but also for tandem cells in which the tunability of QD properties through the capping layer (CL) could be very useful

Implementación de un sistema de gestión de seguridad y salud en el trabajo para disminuir los accidentes en la Empresa Proyectos & Negocios Forestales S.A.C., 2022

Esta investigación tiene como objetivo implementar un SGSST para disminuir los accidentes en la empresa Proyectos & Negocios Forestales S.A.C. Cuando se hizo el diagnóstico línea base de las condiciones que involucran la seguridad, solo se cumplían parcialmente 6 de 8 dimensiones, ello representaba un cumplimiento de 16%, estado pobre, todo lo mencionado anteriormente, no solo repercutía en el clima laboral e incumplimiento de la legislación vigente, sino que como elemento resultante se generaban accidentes de distinto grado de peligrosidad, pero perjudiciales para los trabajadores. Tras la implementación de un SGSST en base a la Ley 29783, siguiendo los pasos ofrecidos por el MTPE para las empresas MyPEs se logró una implementación del sistema en mención, ello en un 70%. Se halló entonces que el problema de la ocurrencia de accidentes puede ser resuelto con la implementación de un SGSST, dado que se obtuvo una reducción de accidentes de un 83%, la accidentabilidad se redujo en un 91.28%, el índice de gravedad decreció en un 47.37% y el índice de frecuencia en un 82.25%

Dissertacion historica, y geographica sobre el meridiano de demarcacion entre los dominios de España, y Portugal...

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 2010Sign. : A-L\p8\

Overexpression of ZePrx in Nicotiana Tabacum Affects Lignin Biosynthesis Without Altering Redox Homeostasis

[Abstract] Class III plant peroxidases (Prxs) are involved in the oxidative polymerization of lignins. Zinnia elegans Jacq. Basic peroxidase (ZePrx) has been previously characterized as capable of catalyzing this reaction in vitro and the role in lignin biosynthesis of several of its Arabidopsis thaliana homologous has been previously confirmed. In the present work, ZePrx was overexpressed in Nicotiana tabacum to further characterize its function in planta with particular attention to its involvement in lignin biosynthesis. Since Prxs are known to alter ROS levels by using them as electron acceptor or producing them in their catalytic activity, the impact of this overexpression in redox homeostasis was studied by analyzing the metabolites and enzymes of the ascorbate-glutathione cycle. In relation to the modification induced by ZePrx overexpression in lignin composition and cellular metabolism, the carbohydrate composition of the cell wall as well as overall gene expression through RNA-Seq were analyzed. The obtained results indicate that the overexpression of ZePrx caused an increase in syringyl lignin in cell wall stems, suggesting that ZePrx is relevant for the oxidation of sinapyl alcohol during lignin biosynthesis, coherently with its S-peroxidase nature. The increase in the glucose content of the cell wall and the reduction of the expression of several genes involved in secondary cell wall biosynthesis suggests the occurrence of a possible compensatory response to maintain cell wall properties. The perturbation of cellular redox homeostasis occurring as a consequence of ZePrx overexpression was kept under control by an increase in APX activity and a reduction in ascorbate redox state. In conclusion, our results confirm the role of ZePrx in lignin biosynthesis and highlight that its activity alters cellular pathways putatively aimed at maintaining redox homeostasis.Xunta de Galicia; ED431C 2018/57AG-U held an FPU grant from MECD (Spain) (FPU13/04835). This research was possible thanks to the funding of Xunta de Galicia (Spain) (ED431C 2018/57

Type II InAs/GaAsSb quantum dots: Highly tunable exciton geometry and topology

External control over the electron and hole wavefunctions geometry and topology is investigated in a p-i-n diode embedding a dot-in-a-well InAs/GaAsSb quantum structure with type II band alignment. We find highly tunable exciton dipole moments and largely decoupled exciton recombination and ionization dynamics. We also predicted a bias regime where the hole wavefunction topology changes continuously from quantum dot-like to quantum ring-like as a function of the external bias. All these properties have great potential in advanced electro-optical applications and in the investigation of fundamental spin-orbit phenomena