Search results for "General Engineering"
showing 10 items of 2407 documents
Computation of a few smallest eigenvalues of elliptic operators using fast elliptic solvers
2001
The computation of a few smallest eigenvalues of generalized algebraic eigenvalue problems is studied. The considered problems are obtained by discretizing self-adjoint second-order elliptic partial differential eigenvalue problems in two- or three-dimensional domains. The standard Lanczos algorithm with the complete orthogonalization is used to compute some eigenvalues of the inverted eigenvalue problem. Under suitable assumptions, the number of Lanczos iterations is shown to be independent of the problem size. The arising linear problems are solved using some standard fast elliptic solver. Numerical experiments demonstrate that the inverted problem is much easier to solve with the Lanczos…
El aprendizaje servicio como propuesta metodológica para una pedagogía crítica
2016
El presente artículo aborda la relación entre la pedagogía crítica y los pilaresfundamentales de la metodología del aprendizaje servicio. Su principal objetivo esdemostrar, de un modo concluyente, la idoneidad del aprendizaje servicio comometodología para alcanzar objetivos pedagógicos tales como la emancipación, latransformación y la justicia social. El trabajo parte de la clarificación de los pilaresfundamentales de la pedagogía crítica, entendida como paradigma filosófico-educativoque emerge de la Teoría Crítica de la Escuela de Frankfurt. Posteriormente, el artículoda cuenta de los fundamentos pedagógicos del aprendizaje servicio, aportandoargumentos que evidencian su capacidad para sat…
Proyectos educativos multidisciplinares y ayuda a la comunidad
2019
This paper relates an experience carried out at a higher education setting, specifically involving 3rd-year students in the Early Childhood Education degree programme. In relation to this, the paper presents an educational model that takes into account the need to develop ethical and social competences and gives importance to interdisciplinary education in real contexts. To this aim, all the academic modules that form part of this degree programme devote 25% of their teaching time and evaluation to the development of an interdisciplinary project. This paper will describe one of these projects, entitled "Solve a real problem", the design of which is informed by service-learning and problem-b…
The photochemical rearrangement of polymeric N-(1-pyridinio) amidates. A novel, aqueous photoresist system
1988
Screening and authentication of herbal formulations based on microextraction-assisted voltammetry of microparticles
2015
A simple solid state electrochemical methodology for screening and authentication of herbal formulations is described. The proposed method is based on the recording of the voltammetric response, in contact with aqueous buffers, of microparticulate films of antioxidant compounds resulting from micro-extraction of dried herbal samples with ethanol or acetone. The obtained voltammetric responses led us to differentiate between diverse active components upon application of bivariate and multivariate chemometric techniques. Resolution of herbal preparations containing two or more components is possible when well-separated voltammetric signals are recorded. In favorable cases, such characteristic…
Effect of Large Changes in Temperature and Pressure on the Thermodynamic Properties of Micellization and on the Distribution Constant of a Polar Solu…
1996
Density measurements of pentanol (PentOH)−dodecyltrimethylammonium bromide (DTAB)−water mixtures as functions of both alcohol and surfactant (mS) concentrations were carried out at 0.1 MPa from 45 to 75 °C and at 19 MPa from 25 to 130 °C. The standard (infinite dilution) partial molar volumes and expansibilities of DTAB in water and the corresponding properties in the micellar phase were calculated from the experimental data. As far as PentOH in DTAB micellar solutions is concerned, with the exception of the standard partial molar volume (V°R) data at 130 °C and 19 MPa, all the V°R vs mS trends are monotonic curves with mS. The data of V°R as a function of mS were treated by means of an equ…
Tailored syntheses of nanostructured silicas: Control of particle morphology, particle size and pore size
1998
Ordered mesoporous silicas with spherical morphology and average particle size in the range between 100 nm and 2 μm were synthesised according to two novel routes. Both synthesis routes used tetraethoxysilane, water, alcohol and aqueous ammonia for producing spherical silica beads. The porosity was created by adding two different kinds of pore structure directing agents to the starting solution: one was an n-alkyltrialkoxysilane which was covalently bonded to the silica framework, the other was an n-alkylamine which acted as a nonionic template. After calcination and post treatment the resulting particles showed a specific surface area up to 1000 m2 g-1, a specific pore volume of up to 0.8 …
Spectroscopic study of molecular associations between riboflavin and some (dihydro) β-carboline derivatives
1993
Abstract The spectrophotometric and thermodynamic properties of molecular complexes of riboflavin (RFN) with some dihydro β-carboline derivatives have been investigated by using electronic absorption and fluorescence spectroscopic methods in aqueous solution. The molecular associations have been examined by means of eletronic absorption spectra, since in each, a new charge transfer-like band has been located, and also by observing the variation of the fluorescence emission of RFN on the solutions. The formation constants for the molecular complexes were determined from absorption data, using the Forster—Hammick—Wardley method. The quenching phenomenon observed in RFN fluorescence is related…
Importancia de la regulación oficial en la vinculación académico-profesional: el caso de las técnicas de auditoría (primeros resultados)
2022
Uno de los objetivos subyacentes de la docencia universitaria actual es intentar conectarla con la realidad profesional con la que se van a encontrar los/as egresados/as con posterioridad en el mercado laboral. En materias muy aplicadas, la existencia de una regulación normativa oficial se convierte en un elemento clave para el éxito de cualquier propuesta docente realizada. Ante dicho contexto la presente investigación trata de estudiar el efecto de la normativa oficial sobre una propuesta de innovación educativa en Ciencia Laborales. A tal efecto, se usa una metodología cuantitativa mediante una encuesta por medio de un cuestionario estandarizado al alumnado de la asignatura de Técnicas d…
A Case Study to evaluate the indoor global quality
2013
This paper proposes two complementary procedures for assessing the global quality comfort: the first one, prevalently objective, is based on the acquisition of microclimate measured data and computed subjective values; the second one, that is purely subjective, uses a questionnaire drawn from the ISO/DP 10551 Recommendation. An application to some lecture-halls and laboratories of the school is here showed.