Invariant manifolds of the Bonhoeffer-van der Pol oscillator

The stable and unstable manifolds of a saddle fixed point (SFP) of the Bonhoeffer-van der Pol oscillator are numerically studied. A correspondence between the existence of homoclinic tangencies (whic are related to the creation or destruction of Smale horseshoes) and the chaos observed in the bifurcation diagram is described. It is observed that in the non-chaotic zones of the bifurcation diagram, there may or may not be Smale horseshoes, but there are no homoclinic tangencies.Comment: 14 pages, 15 figure

A probabilistic model for crystal growth applied to protein deposition at the microscale

A probabilistic discrete model for 2D protein crystal growth is presented. This model takes into account the available space and can describe growing processes of different nature due to the versatility of its parameters which gives the model great flexibility. The accuracy of the simulation is tested against a real protein (SbpA) crystallization experiment showing high agreement between the proposed model and the actual images of the nucleation process. Finally, it is also discussed how the regularity of the interface (i.e. the curve that separates the crystal from the substrate) affects to the evolution of the simulation.Comment: 13 pages, 12 figure

The editorial expression of l'Architecture Vivante: from persuasive systems to critical editing

[EN] L' Architecture Vivante was a French magazine that pioneered in disseminating the productions of the architectural avant-gardes of the early twentieth century. Today with the passage of time, it has become a relevant historical and cultural document. Its editorial expression is the outcome of different semantic variables that came together, although not without conflict. These include the meanings emanating from the editorial decisions made by Jean Badovici, the implicitness in the semantic frameworks that were characteristic of Ediciones Morancé s editorial design, and the contributions of the published oeuvres. Following the methodology used in cultural studies, we will examine these variables as part of a broad cultural context and interpret them from a standpoint of controversy with the reorganization of mass production processes and the integration of marketing in design, aimed at adapting cultural productions to a consumption situation. The analysis will show that, although L Architecture Vivante aligns itself to some extent with the discursive constructs and editorial encodings that sought to determine and contain the meaning of those searches, it also challenges them, in a way that it still preserves a critical value today.[ES] L' Architecture Vivante fue una revista francesa que divulgó tempranamente la producción de las vanguardias arquitectónicas de comienzos del siglo XX, convertida hoy en un relevante documento histórico-cultural. En su expresión editorial convergen, no sin conflicto, distintas variables semánticas: los significados que emanan de las decisiones editoriales de Jean Badovici, los implícitos en los marcos semánticos característicos del diseño editorial de Ediciones Morancé y los aportados por las obras publicadas. Siguiendo la metodología de los estudios culturales, situaremos estas variables en un contexto cultural amplio, leyéndolas en polémica con las políticas de reorganización de los procesos productivos en masa y la integración del marketing en el diseño para adaptar las producciones culturales a una situación de consumo. Se mostrará que, si bien L' Architecture Vivante se alinea en cierta medida con los constructos discursivos y codificaciones editoriales que trataron de fijar y contener el significado de aquellas búsquedas, también los desafía, conservando aún hoy una valencia crítica.Álvarez Benítez, PV. (2022). La expresión editorial de l'Architecture Vivante: de los sistemas persuasivos a la edición crítica. EGA Expresión Gráfica Arquitectónica. 27(44):174-187. https://doi.org/10.4995/ega.2022.15558OJS174187274

Exact solution of the two-dimensional Dirac oscillator

In the present article we have found the complete energy spectrum and the corresponding eigenfunctions of the Dirac oscillator in two spatial dimensions. We show that the energy spectrum depends on the spin of the Dirac particle.Comment: revtex, 6pp. IVIC-CFLE 93/0

Spin precession and spin Hall effect in monolayer graphene/Pt nanostructures

Spin Hall effects have surged as promising phenomena for spin logics operations without ferromagnets. However, the magnitude of the detected electric signals at room temperature in metallic systems has been so far underwhelming. Here, we demonstrate a two-order of magnitude enhancement of the signal in monolayer graphene/Pt devices when compared to their fully metallic counterparts. The enhancement stems in part from efficient spin injection and the large resistivity of graphene but we also observe 100% spin absorption in Pt and find an unusually large effective spin Hall angle of up to 0.15. The large spin-to-charge conversion allows us to characterise spin precession in graphene under the presence of a magnetic field. Furthermore, by developing an analytical model based on the 1D diffusive spin-transport, we demonstrate that the effective spin-relaxation time in graphene can be accurately determined using the (inverse) spin Hall effect as a means of detection. This is a necessary step to gather full understanding of the consequences of spin absorption in spin Hall devices, which is known to suppress effective spin lifetimes in both metallic and graphene systems.Comment: 14 pages, 6 figures. Accepted in 2D Materials. https://doi.org/10.1088/2053-1583/aa882

Co-EP Banach algebra elements

[EN] In this work, given a unital Banach algebra A and a \in A such that a has a Moore-Penrose inverse a^+, it will be characterized when a^+ a - a a^+ is invertible. A particular subset of this class of objects wil also be studied. In addition, perturbations of this class of elements will be studied. Finally, the Banach space operator case will also be consider.The third author is supported by Grant No. 174025 of the Ministry of Science, Technology and Development, Republic of Serbia.Benítez López, J.; Boasso, E.; Rakocevic, V. (2015). Co-EP Banach algebra elements. Banach Journal of Mathematical Analysis. 9(1):27-41. doi:10.15352/bjma/09-1-3S27419

Population ecology of <i>Chaetophractus vellerosus</i>: The first report for an armadillo in South America

The aim of this work was to obtain the first estimates of survival rates (S), capture probability (p) and life expectancy for armadillos in South America by analyzing capture-mark-recapture data obtained from a population of Chaetophractus vellerosus (Gray, 1865) located in Magdalena, Buenos Aires, Argentina. From June 2006 to June 2011, we conducted 16 field surveys that resulted in 365 capture events of 152 adult C. vellerosus. For the survival analysis we used a Cormack-Jolly-Seber (CJS) modelling framework. Interannual variation in S made an important contribution to overall variation in the survival rate of C. vellerosus. The average life expectancy for females and males after attaining sexual maturity was estimated at 1.70 and 1.65 years respectively. The period of lowest survival probability was associated with dry seasons that might have affected the availability of food. This study provides the first estimates of demographic parameters for xenarthrans in South America.Centro de Estudios Parasitológicos y de Vectore

Population ecology of <i>Chaetophractus vellerosus</i>: The first report for an armadillo in South America

The aim of this work was to obtain the first estimates of survival rates (S), capture probability (p) and life expectancy for armadillos in South America by analyzing capture-mark-recapture data obtained from a population of Chaetophractus vellerosus (Gray, 1865) located in Magdalena, Buenos Aires, Argentina. From June 2006 to June 2011, we conducted 16 field surveys that resulted in 365 capture events of 152 adult C. vellerosus. For the survival analysis we used a Cormack-Jolly-Seber (CJS) modelling framework. Interannual variation in S made an important contribution to overall variation in the survival rate of C. vellerosus. The average life expectancy for females and males after attaining sexual maturity was estimated at 1.70 and 1.65 years respectively. The period of lowest survival probability was associated with dry seasons that might have affected the availability of food. This study provides the first estimates of demographic parameters for xenarthrans in South America.Centro de Estudios Parasitológicos y de Vectore

Population ecology of <i>Chaetophractus vellerosus</i>: The first report for an armadillo in South America

The aim of this work was to obtain the first estimates of survival rates (S), capture probability (p) and life expectancy for armadillos in South America by analyzing capture-mark-recapture data obtained from a population of Chaetophractus vellerosus (Gray, 1865) located in Magdalena, Buenos Aires, Argentina. From June 2006 to June 2011, we conducted 16 field surveys that resulted in 365 capture events of 152 adult C. vellerosus. For the survival analysis we used a Cormack-Jolly-Seber (CJS) modelling framework. Interannual variation in S made an important contribution to overall variation in the survival rate of C. vellerosus. The average life expectancy for females and males after attaining sexual maturity was estimated at 1.70 and 1.65 years respectively. The period of lowest survival probability was associated with dry seasons that might have affected the availability of food. This study provides the first estimates of demographic parameters for xenarthrans in South America.Centro de Estudios Parasitológicos y de Vectore

Population ecology of Chaetophractus vellerosus: The first report for an armadillo in South America

The aim of this work was to obtain the first estimates of survival rates (S), capture probability (p) and life expectancy for armadillos in South America by analyzing capture-mark-recapture data obtained from a population of Chaetophractus vellerosus (Gray, 1865) located in Magdalena, Buenos Aires, Argentina. From June 2006 to June 2011, we conducted 16 field surveys that resulted in 365 capture events of 152 adult C. vellerosus. For the survival analysis we used a Cormack-Jolly-Seber (CJS) modelling framework. Interannual variation in S made an important contribution to overall variation in the survival rate of C. vellerosus. The average life expectancy for females and males after attaining sexual maturity was estimated at 1.70 and 1.65 years respectively. The period of lowest survival probability was associated with dry seasons that might have affected the availability of food. This study provides the first estimates of demographic parameters for xenarthrans in South America.Centro de Estudios Parasitológicos y de Vectore