Local triple derivations on real C*-algebras and JB*-triples

We study when a local triple derivation on a real JB*-triple is a triple derivation. We find an example of a (real linear) local triple derivation on a rank-one Cartan factor of type I which is not a triple derivation. On the other hand, we find sufficient conditions on a real JB*-triple E to guarantee that every local triple derivation on E is a triple derivation

Una experiencia en la plataforma Edu 2.0 como estrategia para desarrollar las capacidades investigativas en los estudiantes

La investigación científica lo largo de la historia ha sido considerad un tema complejo, por ende difícil de comprender por los estudiantes de pregrado y posgrado, más aún cuando no se ha desarrollado a lo largo de la currículo, no se han definido asignaturas que logren desarrollar la capacidad de investigación. Por esta razón se optó por utilizar un método y una herramienta para corregir estas dificultades y proveer en los estudiantes de lo necesario para lograr los objetivos de las asignaturas de investigación. En el contexto de la educación superior lo que se pretende es desarrollar e incrementar un sistema de aprendizaje seguro y práctico, acorde con las expectativas y las necesidades del futuro profesional que se está formando y con las exigencias que la sociedad espera de este. De ahí que, el mismo programa y contenido de la asignatura Prácticas I requiere de un método de enseñanza utilizando la plataforma Edu 2.0 y por tanto un entorno de aprendizaje constructivista. El estudio de caso se dio con la interacción y actuación, donde los estudiantes deben trabajar juntos ayudándose unos a otros, usando una variedad de instrumentos y recursos informativos que permitan la búsqueda de los objetivos de aprendizaje y actividades para la solución de problemas. Al mismo tiempo que la constante innovación y desarrollo de las nuevas tecnologías de información y de la comunicación nos proporcionan herramientas muy útiles para el desarrollo de ese aprendizaje,como la plataforma Edu 2.

Local triple derivations on C*-algebras

We prove that every bounded local triple derivation on a unital C*-algebra is a triple derivation. A similar statement is established in the category of unital JB*-algebras.Comment: 12 pages, submitte

2-local triple homomorphisms on von Neumann algebras and JBW∗^*-triples

We prove that every (not necessarily linear nor continuous) 2-local triple homomorphism from a JBW$^*$-triple into a JB$^*$-triple is linear and a triple homomorphism. Consequently, every 2-local triple homomorphism from a von Neumann algebra (respectively, from a JBW$^*$-algebra) into a C$^*$-algebra (respectively, into a JB$^*$-algebra) is linear and a triple homomorphism

Sobre la ocurrencia del cretáceo superior marino en Coihaique , Provincia de Aisén

Using the CCSD­(T) model, we evaluated the intermolecular potential energy surfaces of the He–, Ne–, and Ar–phosgene complexes. We considered a representative number of intermolecular geometries for which we calculated the corresponding interaction energies with the augmented (He complex) and double augmented (Ne and Ar complexes) correlation-consistent polarized valence triple-ζ basis sets extended with a set of 3s3p2d1f1g midbond functions. These basis sets were selected after systematic basis set studies carried out at geometries close to those of the surface minima. The He–, Ne–, and Ar–phosgene surfaces were found to have absolute minima of −72.1, −140.4, and −326.6 cm^–1 at distances between the rare-gas atom and the phosgene center of mass of 3.184, 3.254, and 3.516 Å, respectively. The potentials were further used in the evaluation of rovibrational states and the rotational constants of the complexes, providing valuable results for future experimental investigations. Comparing our results to those previously available for other phosgene complexes, we suggest that the results for Cl₂–phosgene should be revised

Ferromagnetism in bulk Co-Zn-O

The origin of ferromagnetism in diluted magnetic semiconductors is still an open question, yielding a great deal of research across the world. This work focuses on the Co-Zn-O system. Room-temperature ferromagnetism is observed after a partial reaction of Co_3O_4 and ZnO, which can be ascribed neither to carrier mediation nor segregated cobalt metallic clusters. Another mechanism is yielding room-temperature ferromagnetism. This mechanism is associated with a partial reaction of ZnO and Co_3O_4 grains, and always appears when the starting phases (Co_3O_4 and ZnO) are present in the sample, suggesting that interfaces are involved in the origin of the observed ferromagnetism

Electronically Tunable Phase Response for Phased array Patches

The design and prototyping of radiating elements with tunable phase response, for reconfigurable patch array antennas, is presented. Different options are found in the technical literature to obtain feasible reconfigurable array antennas: placing the active circuitry in the transmission lines or directly over the radiating element, obtaining the desired phase shift for each radiating element of the array. In this reported work, the second option is selected and active radiating elements at 12 GHz are designed and prototyped

Origin of Small Barriers in Jahn–Teller Systems:Quantifying the Role of 3d–4s Hybridization in the Model System NaCl:Ni⁺

Despite its relevance, the microscopic origin of the energy barrier, B, between the compressed and elongated geometries of Jahn–Teller (JT) systems is not well understood yet because of a lack of quantitative data about its various contributions. Seeking to clear up this matter, we have carried out both periodic and cluster ab initio calculations on the model system NaCl:Ni+. This system is particularly puzzling because, according to experimental data, its barrier is much smaller than that for other d9 and d7 ions in similar lattices. All calculations performed on the model system lead, in fact, to values |B| ≤ 160 cm–1, which are certainly smaller than B = 500 cm–1 derived for NaCl:M2+ (M = Ag, Rh) or B = 1024 cm–1 obtained for KCl:Ag2+. As a salient feature, analysis of calculations carried out as a function of the Qθ (3z2 – r2) coordinate unveils the microscopic origin of the barrier. It is quantitatively proven that the elongated geometry observed for NaCl:Ni+ is due to the 3d–4s vibronic admixture, which is slightly larger than the anharmonicity in the eg JT mode that favors a compressed geometry. The existence of these two competing mechanisms explains the low value of B for the model system, contrary to cases where the complex formed by d9 or d7 ions is elastically decoupled from the host lattice. Although the magnitude of B for NaCl:Ni+ is particularly small, the tunneling splitting, 3Γ, is estimated to be below 9 cm–1, thus explaining why the coherence is easily destroyed by random strains and thus a static JT effect is observed experimentally. As a main conclusion, the barrier in JT systems cannot be understood neglecting the tiny changes of the electronic density involved in small distortions. The present calculations reasonably explain the experimental g tensor of NaCl:Ni+, pointing out that the d–d transitions in NiCl65– are much smaller than those for CuCl64– and the optical electronegativity of Ni+ is only around 1.</p

Network equilibration and first-principles liquid water.

Motivated by the very low diffusivity recently found in ab initio simulations of liquid water, we have studied its dependence with temperature, system size, and duration of the simulations. We use ab initio molecular dynamics (AIMD), following the Born-Oppenheimer forces obtained from density-functional theory (DFT). The linear-scaling capability of our method allows the consideration of larger system sizes (up to 128 molecules in this study), even if the main emphasis of this work is in the time scale. We obtain diffusivities that are substantially lower than the experimental values, in agreement with recent findings using similar methods. A fairly good agreement with D(T) experiments is obtained if the simulation temperature is scaled down by approximately 20%. It is still an open question whether the deviation is due to the limited accuracy of present density functionals or to quantum fluctuations, but neither technical approximations (basis set, localization for linear scaling) nor the system size (down to 32 molecules) deteriorate the DFT description in an appreciable way. We find that the need for long equilibration times is consequence of the slow process of rearranging the H-bond network (at least 20 ps at AIMDs room temperature). The diffusivity is observed to be very directly linked to network imperfection. This link does not appear an artifact of the simulations, but a genuine property of liquid water

Implementation of an End-to-End Standards-based Patient Monitoring Solution

A proof-of-concept design of a patient monitoring solution for intensive care unit environments has been presented. It is end-to-end standard-based, using ISO/IEEE 11073 (X73) in the bedside environment and EN13606 to communicate the information to an electronic healthcare record (EHR) server. At the bedside end, the system is a plug-and-play sensor network communicating with a gateway that collects medical information and sends the data to a monitoring server. The monitoring server transforms this information into an EN13606 extract to be stored on the EHR server. The system has been implemented to comply with the last X73 and EN13606 available versions and tested in a laboratory environment to demonstrate the feasibility of an end-to-end standard-based solution