6,211 research outputs found
Investigation of crystal field, magnetic frustration and magnetization reversal effects in 4f and 3d oxides
No full textThis thesis deals with the investigation of single-ion excitations, magnetic frustration, and magnetization reversal phenomena. We have employed neutron scattering, μ+SR, and computational methods for these studies.
Inverse spinel oxide Co2VO4 belongs to the family of spinel vanadates where cobalt and vanadium ions occupy the spinel B-site equally. This system exhibits magnetization reversal for temperatures below 65 K. Magnetization studies reveal three anomalies involving collinear and non-collinear ferrimagnetism phase and magnetization reversal crossover. Neutron diffraction analysis of Co2VO4 unveils that the evolution of relative balance between the two sublattice moments leads to ferrimagnetic phase and magnetization reversal. DFT calculation and μ+SR results suggest delocalization -localization crossover as the underlying microscopic mechanism for magnetization reversal.
Rare earth oxide SrTm2O4 belongs to the family of SrLn2O4 where two inequivalent Tm3+s form two zig-zag chains along the orthorhombic c-axis. An earlier study on SrTm2O4 reports the absence of long- or short-range order down to 65 mK. The crystal fields and exchange interactions in SrTm2O4 were studied to examine the absence of order. The crystal fields in SrTm2O4 were modeled using DFT and the effective charge (EC) model. The EC model describes the system well and suggests ꞁJ,mj > = ꞁ6,0> dominates the ground state of both Tm3+s. The exchange interactions extracted from low-energy dispersing excitations using random phase approximation suggest that Tm2 chains are frustrated and Tm1 chains could form dimers. The critical ratio calculated from exchange interaction indicates SrTm2O4 cannot undergo a thermal second-order phase transition confirming the absence of order. μ+SR results show oscillations in polarization evolution spectra; these are typically associated with muon precession due to the system’s long-range order. Modeling precession frequency vs. temperature reveals that these oscillations originate due to nuclear hyperfine enhancement. Additionally, the magnetic field application induces long-range order, with Tm2 function as polarized paramagnet whereas Tm1 above 4 T transitions into XY-AFM phase
Métricas de autor Laura Elizabeth Castro Jiménez
No full textInforme de las métricas de autor de la Dra. Laura Elizabeth Castro Jiménez de las publicaciones indexadas en Google Académico cuyo objetivo es entregar un insumo para el fortalecimiento de las capacidades y potencialidades de los autores de la Universidad Santo Tomás en el posicionamiento y visibilidad de sus publicacionesReport of the author metrics of Laura Elizabeth Castro Jiménez of the publications indexed in Google Scholar whose objective is to provide an input for the strengthening of the capacities and potentialities of the authors of the Santo Tomás University in the positioning and visibility of their publications.http://unidadinvestigacion.usta.edu.c
Clinical patterns and outcomes of ischaemic colitis: Results of the Working Group for the Study of Ischaemic Colitis in Spain (CIE study)
No full textMontoro, M.A., Brandt, L.J., Santolaria, S., Gomollon, F., Puértolas, B.S., Vera, J., Bujanda, L., Cosme, A., Cabriada, J.L., Durán, M., Mata, L., Santamaría, A., Ceña, G., Blas, J.M., Ponce, J., Ponce, M., Rodrigo, L., Ortiz, J., Muñoz, C., Arozena, G., Ginard, D., López-Serrano, A., Castro, M., Sans, M., Campo, R., Casalots, A., Orive, V., Loizate, A., Titó, L., Portabella, E., Otazua, P., Calvo, M., Botella, M.T., Thomson, C., Mundi, J.L., Quintero, E., Nicolás, D., Borda, F., Martinez, B., Gisbert, J.P., Chaparro, M., Bernadó, A.J., Gómez-Camacho, F., Cerezo, A., Nuñez, E.C
"Test me and treat me" - attitudes to vitamin D deficiency and supplementation: a qualitative study
No full text© 2015 BMJ Open, "Test me and treat me"-attitudes to vitamin D deficiency and supplementation: a qualitative study. This manuscript version is made available under the Creative Commons Attribution Licens
A method for detecting the profile of an author
No full textThis paper presents a method for detecting an author’s profile using the following two elements: gender and age. This is based on a set of dialogues, written in two languages: English and Spanish, provided for Author Profiling competence within the evaluation forum "Uncovering Plagiarism, Authorship, and Social Software Misuse" (PAN2018). Counts of lexical, semantic, and syntactic characteristics are used to generate a two-phase classification system, which first classifies gender and then age. The results obtained show that, with the amount of data available, it is possible to characterize both the age and gender of an author with an accuracy greater than 50%. However, these values could be improved by having more evidence of information in the training data.Silva, JesusGarcía, SilviaBinda, María AlejandraMarin Gonzalez, FredyBarrios, RosioLeon Castro, Bellani
Conference Institutional archives for research: experiences and projects in Open Access Istituto Superiore di Sanità Rome, 30 November - 1 December 2006
No full textThe Congress was organised into four sessions: 1) Open Access (OA) and authors: support from the international community; 2) OA in Italy: knowledge and tools to write and search; 3) institutional policies for OA; 4) opportunities and services to develop OA. It was aimed at achieving the following objectives: a) make authors of biomedical publications aware of the benefits of depositing research material in digital open archives and publishing in OA peer-reviewed journals; b) outline the impact of the OA publishing model on the assessment of research output; c) enhance the adoption of policies encouraging the OA paradigm; d) promote cooperation between research institutions in Italy and abroad to share resources and experiences on institutional repositories. A useful introductory bibliography on the OA publishing model in the biomedical field is included in the Appendix
Hablar a plantas: un diálogo entre las artes plásticas y la medicina tradicional en el departamento del Chocó
No full textEn este artículo, la artista plástica e investigadora Astrid González Quintero presenta resultados de un proyecto de investigación sobre las plantas mágico-religiosas, las mitologías y los rituales de sanación en el Pacífico colombiano. Con una propuesta metodológica decolonial, en parte antropología familiar y en parte ficción, la artista hace visibles las tradiciones espirituales afrodiaspóricas colombianas, al tiempo que salvaguarda su privacidad y las protege de su exotización por parte de miradas externas. En su práctica artística Gonzalez Quintero combina video, performance e instalación, y comparte su interés por traer al espacio público cosmogonías negras que se han visto con recelo por causa de las herencias coloniales en el país
Hablar a plantas: un diálogo entre las artes plásticas y la medicina tradicional en el departamento del Chocó
No full textEn este artículo, la artista plástica e investigadora Astrid González Quintero presenta resultados de un proyecto de investigación sobre las plantas mágico-religiosas, las mitologías y los rituales de sanación en el Pacífico colombiano. Con una propuesta metodológica decolonial, en parte antropología familiar y en parte ficción, la artista hace visibles las tradiciones espirituales afrodiaspóricas colombianas, al tiempo que salvaguarda su privacidad y las protege de su exotización por parte de miradas externas. En su práctica artística Gonzalez Quintero combina video, performance e instalación, y comparte su interés por traer al espacio público cosmogonías negras que se han visto con recelo por causa de las herencias coloniales en el país
Hablar a plantas: un diálogo entre las artes plásticas y la medicina tradicional en el departamento del Chocó
No full textEn este artículo, la artista plástica e investigadora Astrid González Quintero presenta resultados de un proyecto de investigación sobre las plantas mágico-religiosas, las mitologías y los rituales de sanación en el Pacífico colombiano. Con una propuesta metodológica decolonial, en parte antropología familiar y en parte ficción, la artista hace visibles las tradiciones espirituales afrodiaspóricas colombianas, al tiempo que salvaguarda su privacidad y las protege de su exotización por parte de miradas externas. En su práctica artística Gonzalez Quintero combina video, performance e instalación, y comparte su interés por traer al espacio público cosmogonías negras que se han visto con recelo por causa de las herencias coloniales en el país
On some singular Sturm-Liouville equations and a Hardy type inequality
No full textThe main body of this dissertation can be divided into two separate topics. The first topic deals with a Hardy type inequality for functions belonging to the Sobolev space , where and is a smooth bounded domain in , . We show that for such functions , one has [ orm{partial^kpt{frac{partial^ju(x)}{d(x)^{m-j-k}}}}_{L^1(Omega)}leq Corm{u}_{W^{m,1}(Omega)}, ] where are non-negative integers such that and , and is a smooth positive function which coincides with near . The second topic deals with the study of the singular Sturm-Liouville operator {,} where . We develop a linear theory for such operator by introducing suitable weighted Sobolev spaces and prove existence and uniqueness for equations of the form under both homogeneous and non-homogeneous boundary data at the origin. In addition, the spectrum of the operator is fully described. Finally, we prove existence, non-existence and uniqueness results for positive solutions of the non-linear singular Sturm-Liouville equation , where , and are parameters.Ph. D.Includes bibliographical referencesIncludes vitaby Hernán Castr
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