Search results for "Ida"
showing 10 items of 33009 documents
Validación de la Escala de Satisfacción con la Vida y su relación con las dimensiones del Autoconcepto en universitarios peruanos
2018
Life satisfaction has been the object of several studies, mostly assessed with the Satisfaction with Life Scale (SWLS). Recently, interest has been shown in the relationship between life satisfaction and self-concept, because life satisfaction seems to depend on the cultural context. The purpose of this research was to study the properties of the SWLS in a sample of Peruvian students, and to analyze the relationship between life satisfaction and self-concept in the Peruvian context. The study population consisted of 527 university students from Lima, Peru. Firstly, a confirmatory factor analysis was estimated and assessed, and reliability estimates of the scale and its items were calculated…
Validación del Autoconcepto Forma 5 en Universitarios Peruanos: Una Herramienta para la Psicología Positiva
2015
ResumenEl autoconcepto, aunque central en la psicología tradicional, ha cobrado importancia recientemente en el contexto de la psicología positiva. El Autoconcepto Forma 5 (AF5) es una medida muy utilizada en el contexto hispanohablante. Sin embargo, no existen estudios sobre sus propiedades psicométricas más allá de la fiabilidad en población peruana. El objetivo es presentar las propiedades psicométricas de la escala multidimensional AF5 en universitarios peruanos. Se recogió una muestra de 527 estudiantes universitarios. La encuesta incluyó, además del AF5, medidas de esperanza disposicional y satisfacción con la vida. Se llevó a cabo un análisis factorial confirmatorio para evaluar la v…
Cádiz en Charcas: conjeturas e indicios
2012
Este es un artículo de historia constitucional. Se centra en la relación entre la Constitución española de 1812 y la Constitución boliviana de 1826. Su conclusión principal niega la idea de que, por el solo hecho de que ambas fueron cartas liberales contemporáneas entre sí escritas en la misma lengua, la primera Constitución haya influenciado en la segunda. Al contrario, toma a las semejanzas de redacción como un mero mecanismo de auxilio técnico, pero no por una fuente de influencia. Y, no las califica así, porque la influencia supone una relación de autoridad moralmente justificada, lo que, precisamente, estaba ausente entre el poder metropolitano y sus colonias. Una serie de documentos h…
Revisionismo histórico y racismo en la jurisprudencia constitucional : los límites de la libertad de expresión (a propósito de la STC 235/2007)
2007
Después de plantear la contradicción existente en la jurisprudenciaconstitucional que, por una parte, admite el revisionismo histórico conel límite del respeto a la dignidad y, por otra parte, reconoce con lamáxima amplitud la libertad ideológica, se analiza la STC 235/2007que ha declarado inconstitucional el delito de negación del genocidioy, en cambio, ha considerado constitucional la penalización de la justificacióndel genocidio. Esta sentencia ha clarificado parcialmente lasituación del revisionismo histórico y, en general, de la difusión de ideascontrarias a la Constitución pero sigue existiendo aquella contradicción;no obstante, ha aportado elementos como la distinción entreideas y ac…
Simultaneous Synthesis and Consolidation of Nanostructured MoSi2
2002
A new process combining electric field activation and the imposition of pressure from mechanically activated powder mixtures is demonstrated as a means to simultaneously synthesize and densify nano-MoSi2 in one step. Nanophase reactants (Mo + 2Si) produced by mechanical activation are reacted by field activation with the simultaneous application of a uniaxial pressure. Mo + 2Si powders were comilled in a specially designed planetary mill to obtain nanometric reactants but to avoid formation of any product phases. These were then subjected to high alternating currents (1600 A) and pressures of 106 MPa. Under these conditions, a reaction is initiated and completed within a short period of tim…
Design and experimental validation of a magnetic device for stem cell culture.
2020
Cell culture of bone and tendon tissues requires mechanical stimulation of the cells in order to mimic their physiological state. In the present work, a device has been conceived and developed to generate a controlled magnetic field with a homogeneous gradient in the working space. The design requirement was to maximize the magnetic flux gradient, assuring a minimum magnetizing value in a 15 mm × 15 mm working area, which highly increases the normal operating range of this sort of devices. The objective is to use the machine for two types of biological tests: magnetic irradiation of biological samples and force generation on paramagnetic particles embedded in scaffolds for cell culture. The…
High temperature oxidation of Mg2(Si-Sn)
2016
Abstract High temperature oxidation of Mg 2 Si 1- x Sn x alloys ( x = 0.1 ⿿ 0.6) has been investigated. The oxidation rate was slow for temperatures below 430 °C. In the temperature range between 430⿿500 °C all the alloys exhibited breakaway oxidation. The onset temperature of the breakaway region in general decreased with increasing level of Sn in the alloy. The breakaway behavior is explained by a combination of the formation of a non-protective MgO layer and the formation of Sn-rich liquid at the interface between the oxide and Mg depleted Mg 2 Sn.
Oxidation resistance of Ti 3 AlC 2 and Ti 3 Al 0.8 Sn 0.2 C 2 MAX phases: A comparison
2019
Ti3AlC2 and Ti3Al0.8Sn0.2C2 MAX phase powders are densified using Spark Plasma Sintering technique to obtain dense bulk materials. Oxidation tests are then performed over the temperature range 800-1000°C under synthetic air on the two different materials in order to compare their oxidation resistance. It is demonstrated that, in the case of the Ti3Al0.8Sn0.2C2 solid solution, the oxide layers consist in TiO2, Al2O3 and SnO2. The presence of Sn atoms in
Improving the high temperature oxidation resistance of Ti-β21S by mechanical surface treatment
2020
The improvement of the high temperature oxidation resistance of titanium alloys is currently a technological challenge. Mechanical surface treatments as shot-peening (SP) have shown their ability to improve the behaviour of pure zirconium and titanium. However, shot-peening treatments can induce a significant surface contamination. Laser shock peening (LSP) appears as a good alternative. Here, we have investigated the effect of SP and LSP treatments on the HT oxidation behavior of Ti-β21S. Samples treated by these methods have been compared to untreated ones for long exposures (3000 h) at 700 °C in dry air. The samples placed in a furnace at 700 °C were periodically extracted to be weighed.…
Thermal oxidation of the intermetallic phases Al 8 Mo 3 and AlMo 3
2017
Abstract The thermal oxidation reactions of the intermetallic phases Al8Mo3 and AlMo3 were investigated and analyzed by ex-situ powder-x-ray diffraction (XRD), difference thermal analysis (DTA), thermogravimetry (TGA), and infrared spectroscopy (IR). The initial oxidation reactions in air were found to yield Al2O3 and AlMo3 in the case of Al8Mo3 (Tonset =725 °C), and MoO3 as well as Al8−xMo3 (Tonset =435 °C) for the pure intermetallic phase AlMo3, respectively. Thus, both intermetallic phases are coexisting in an equilibrium within a temperature range of 300 °C under oxidizing conditions. The formation of β-Al2(MoO4)3 followed the second oxidizing process of the respective minority componen…