Search results for "LAB"
showing 10 items of 7932 documents
ACQUISITION OF STUDENT SCIENTIFIC INQUIRY SKILLS: CENTRALISED EXAMINATION RESULTS IN CHEMISTRY
2016
From 2011, the new educational standard in Latvia in the framework of the educational reform on the centralised examination (CE) in chemistry stipulates students to demonstrate the inquiry skills they have mastered. The purpose of this study is to find out the students’ inquiry skills by analysing the CE results in chemistry. This study addresses the following research questions: (a) To what extent are the centralised examination inquiry skills measured according to the standard outcomes? (b) What information on how students have mastered the inquiry skills in chemistry is available from the CE results for the period of 2011-2015? (c) Does measuring the inquiry skills using inquiry-based la…
Parameters identification of the complex impedance model of the PEM fuel cell using Matlab/Simulink
2017
In this work, we present a new technical method for identifying the complex impedance model parameters of a Proton Exchange Membrane (pEM) Fuel Cell for on-board diagnosis in real time. The study of the PEM Fuel Cell modelling is important in order to understand the physical phenomena that occurring in this green renewable energy source. A diagnosis method is presented by analyzing the behavior of the complex impedance. For this, we present the identification method of the various complex impedance parameters; this identification is based on mathematical methods using the least squares method and the interpolation analysis method. The results are obtained using Matlab/Simulink tools and all…
Rates of convergence to equilibrium for collisionless kinetic equations in slab geometry
2017
This work deals with free transport equations with partly diffuse stochastic boundary operators in slab geometry. Such equations are governed by stochastic semigroups in $L^{1}$ spaces$.\ $We prove convergence to equilibrium at the rate $O\left( t^{-\frac{k}{2(k+1)+1}}\right) \ (t\rightarrow +\infty )$ for $L^{1}$ initial data $g$ in a suitable subspace of the domain of the generator $T$ where $k\in \mathbb{N}$ depends on the properties of the boundary operators near the tangential velocities to the slab. This result is derived from a quantified version of Ingham's tauberian theorem by showing that $F_{g}(s):=\lim_{\varepsilon \rightarrow 0_{+}}\left( is+\varepsilon -T\right) ^{-1}g$ exists…
Electron crystallography and non-linear optics
1999
Electron crystallography can be used to obtain specific information about molecular parameters such as the polarisability, dipole moment, and hyperpolarisability. In this, work we show how a combination of quantum mechanics and simulation methods can be used to solve several unknown organic structures and how the calculated molecular parameters can be used to predict the corresponding physical properties of the crystals.
2D slab models of TiO2 nanotubes for simulation of water adsorption: Validation over a diameter range
2020
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2019/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART 2 .
Collaborative Writing with Wikis: Pedagogical and Technological Implications for Successful Implementation in Teacher Education
2012
Wikis have been promoted as tools that foster collaborative learning and writing. They enable multiple users to edit a document collaboratively and support online written communication between participants. While most wiki research is based on students’ subjective perceptions of the wiki learning environment, a number of studies have drawn on the data log that is automatically generated by wikis. The data log enables the analysis of students’ activities performed on the wiki in terms of work distribution, level of contribution, types of activities, timing of contribution, and work intervals. This information is more reliable to analyze collaborative writing activities than subjective percep…
Work engagement y su relación con la performance y la satisfacción laboral
2018
El presente trabajo, basado en los aportes de la Psicología Organizacional Positiva (POP),consistió en un análisis del concepto de Work Engagement. Por un lado, se buscó explorar las concepciones que tienen personas con personal a cargo sobre el work engagement mediante entrevistas realizadas a 38 voluntarios de la población general de la Ciudad de Buenos Aires y el conurbano bonaerense (18 hombres, 47.37%; 20 mujeres, 52.63%). La edad promedio fue de 49.87 años (DE = 9.48). Del análisis de contenido realizado se obtuvieron una serie de categorías que reflejan concepciones acerca del engagement. Por ejemplo, los participantes consideraron que las personas con engagement son aquellasque mues…
Respuestas psicobiológicas en profesores al inicio y al final de un curso académico
2013
La evidencia científica indica que el estrés laboral incrementa el riesgo de enfermedad cardiovascular. Las respuestas emocionales, cardiovasculares y endocrinas se ven afectadas por la experiencia diaria. La percepción de estrés, el estado de ánimo negativo, la frecuencia cardíaca (FC) y la presión arterial (PA) incrementan en los periodos laborales. La respuesta del cortisol (C) no es tan clara, existiendo resultados contradictorios. El objetivo de este trabajo es analizar en profesores los marcadores de estrés durante dos jornadas laborales. Además se evaluó el papel del género en la respuesta de estrés en 49 profesores. Para ello, se midió la percepción de estrés, el estado de ánimo, la…
Model of psychosocial intervention in organizations opposed to job stress: operational strategy
2009
Artículos originales [ES] El artículo presenta un modelo de actuación frente a los factores de riesgo psicosociales derivados del estrés laboral. Primeramente relaciona los principales efectos que ocasiona en toda organización el estrés laboral. Al mismo tiempo establece sus prioridades de actuación, para acto seguido indicar las actividades que deben ejecutarse. Dentro de esta fase de actuación, diferencia aquellas que van dirigidas a la organización de forma colectiva, cuya prioridad es manifiesta, frente a las acciones que deben ofrecerse a los afectados de forma individualizada. Así pues, se trata de un modelo de intervención que interactúa tanto en las medidas organizativas generales c…
Psychobiological responses at the beginning and the end of an academic year in teachers
2013
Evidence shows that work stress increases risk of cardiovascular disease. Emotional, cardiovascular and endocrine responses are affected by day-to-day experience. Perceived stress, negative mood, heart rate (HR) and blood pressure (BP) increase in working periods. Cortisol (C) response is not so clear, there being contradictory results. The main purpose is to study stress markers in two working days in teachers. Moreover, we evaluate the role of gender in stress markers in 49 school teachers. Perceived stress, mood, BP, HR, and C were measured at the beginning and at the end of an academic year. Results show that psychological and heart rate responses to a working day were different at the …