Search results for "magnetism."
showing 10 items of 1879 documents
Fabricación de fibras de cristal fotónico y grabación de redes de Bragg
2010
Los trabajos y experimentos desarrollados en esta tesis han ido dirigidos fundamentalmente a la fabricación de fibras de cristal fotónico y a la grabación de redes de Bragg en éstas. Este proyecto se ha desarrollado en dos partes. La primera parte consiste en conocer las características y propiedades de las redes de Bragg grabadas en fibras ópticas. Describe cuáles son las técnicas empleadas para la fabricación de redes de Bragg y explica el método utilizado en la grabación de redes en este trabajo, enfatizando la técnica de apodización de redes de Bragg que se implementó como mejora en el sistema de grabación previamente existente. Se describen algunas de las aplicaciones desarrolladas en …
Azido and thiocyanato bridged dinuclear Ni(II) complexes involving 8-aminoquinoline based Schiff base as blocking ligands: Crystal structures, ferrom…
2020
Abstract The use of two 8-aminoquinoline-based tridentate N3-donor rigid Schiff base ligands (L1 and L2) with Ni(II) in the presence of the pseudohalides, NaN3 and NaSCN results in the crystallization of the two novel Ni(II) dimers: [Ni2(L1)2(µ1,1′-N3)2(N3)2] (1) and [Ni2(L2)2(µ1,3-NCS)2(NCS)2] (2). Both complexes are centrosymmetric Ni(II) dimers where the Schiff base ligands coordinate the octahedral Ni(II) centres in a mer configuration with one terminal and two bridging pseudohalide ligands in the remaining positions. Complex 1 shows Ni(II) ions connected by a double µ1,1′-N3− bridge whereas in complex 2 the Ni(II) ions are connected by a double µ1,3-NCS− bridge. The magnetic properties…
El concepto de fuerza electromotriz en cursos introductorios de física en la universidad: dificultades de aprendizaje y la presentación del concepto …
2012
La persistencia de concepciones alternativas en los estudiantes, incluso de niveles universitarios y entre profesores son dificultades de la práctica docente sin resolver que ponen en evidencia la necesidad de investigar en las dificultades de comprensión de unos y otros, para orientar la búsqueda de estrategias que disminuyan la incidencia de tales concepciones. Esta investigación contribuye a poner en evidencia que algunas concepciones alternativas (interpretaciones de los estudiantes que están en conflicto con el concepto formal como es entendido por un físico experto) acerca del concepto de fuerza electromotriz, enmarcado en la teoría electromagnética son comunes entre estudiantes quien…
Generación y Validación de algoritmos para la obtención de la temperatura de la superficie terrestre utilizando técnicas de Teledetección en el infra…
2014
La temperatura de superficie terrestre, LST (por sus siglas en inglés), es uno de los principales parámetros en el estudio de balance energético y de masa entre la atmosfera y el suelo, en particular, en la estimación de la evapotranspiración y el estrés hídrico que pueda sufrir la vegetación (Hall et al, 1992; Sellers, et al., 1995; Anderson, et al., 1997; Sánchez, et al. 2008). Además, la LST es necesaria como dato inicial en modelos de predicción meteorológica (Barton, et al. 1989; Gouturbe, et al. 1993), evaluación de daños provocados por las heladas (Caselles y Sobrino 1989), y detección de incendios forestales (Calle, et al. 2005), entre otros muchos. La LST puede considerarse también…
Magnetic, Soft and Active Matter section: Abstract Book : Monday, 30 January 2023, 10.00 AM, online
2023
This abstract book is made for the Magnetic Soft and Active Matter section of the 81st International Scientific Conference of the University of Latvia, held on January 30, 2023. It is organized primarily by the MMML lab (Lab of Magnetic Soft Materials). The section includes reports on the latest developments in the research on magnetism and its interplay with active and soft systems.
Magnetically Driven Swirling Flow Guided by Steady Magnetic Field and Imposed Rotation
1998
Ferromagnetic coupled μ-phenoxo-μ-carboxylato heterodinuclear complexes based on the Cr(salen) moiety: Structural and magnetic characterization
2009
The synthesis, crystal structure, and magneto-chemical characterization of two new unprecedented μ-phenoxo-μ-carboxylato heterodinuclear complexes based on the Cr(salen) moiety (salen = N,N′-bis(salicylidene)ethylenediamine), [MII(O2C(CH3)3)(OH2)2(μ-O2C(CH3)3)(μ-salen)CrIII(O2C(CH3)3)], M = Ni (2), Co(3) are reported. The dinuclear complexes were obtained starting from the mononuclear trans-[Cr(salen)(CN)2]PPh4 (1), whose crystal structure is also reported. They show a trans arrangement of the Cr(salen) unit, bridging through the phenolate O atoms to a second metal center. An additional μ2-O2-carboxylato bridge and a further monodentating carboxylate ligand complete the roughly octahedral C…
On the carrier of inertia
2018
A change in momentum will inevitably perturb the all-embracing vacuum, whose reaction we understand as inertia. Since the vacuum's physical properties relate to light, we propose that the vacuum embodies photons, but in pairs without net electromagnetic fields. In this physical form the free space houses energy in balance with the energy of matter in the whole Universe. Likewise, we reason that a local gravitational potential is the vacuum in a local balance with energy that is bound to a body. Since a body couples to the same vacuum universally and locally, we understand that inertial and gravitational masses are identical. By the same token, we infer that gravity and electromagnetism shar…
Elektrophysiologische Untersuchung zum Einsatz von Streptolysin O und Natrium-Hyaluronat zur Permeabilitätsmodulation der Membran des runden Fensters…
2003
Background: The round window membrane (RWM) acts like a barrier for topically applied substances into the middle ear preventing diffusion into the perilymphatic fluid compartment. Material and Method: In an animal model, modulation of the permeability of the RWM was attempted using Streptolysin-O (SLO) in various concentrations and sodium hyaluronate. Thereafter, the effect of intratympanically applied Lidocain 2% on hearing threshold measured by auditory brainstem response was tested for Lidocain 2 % and Lidocain 2 % in combination with SLO or sodium hyaluronate. Results: The results show that both, SLO and sodium hyaluronate, influence the effect of Lidocain 2 % on hearing thresholds as a…
Magnetic properties of Co2Mn1−xFexSi Heusler alloys
2006
Co2Mn1−xFexSi Heusler alloys with Fe concentration x = 0–0.4 as prepared by arc melting show a L21 long range order for all Fe concentrations. Magnetic properties of Co2Mn1−xFexSi Heusler alloys were investigated by magnetometry and circular magnetic dichroism. The magnetization of the Fe doped Heusler alloys is in agreement with the Slater–Pauling values expected for half-metallic ferromagnets. Element specific magnetic moments as determined by x-ray absorption using the total electron yield method are in disagreement with theoretical predictions for x = 0 but approach the predicted values as the Fe concentration increases. Surprisingly small Fe concentration increases the magnetic moments…