Search results for " PRIN"
showing 10 items of 1809 documents
Heat and mass flows coupled with stress in a continuous medium
1996
Abstract The present paper is concerned with the formulation of the generalization of theories describing heat and mass flows in a continuous medium. The considerations are based on the non-equilibrium thermodynamics. As a result the fundamental equations for the mass and heat fluxes and for the thermodynamic and mechanical fields, are obtained and the corresponding set of differential equations is formulated. Certain differences are pointed out between the general theories presented here and the thermodiffusion theory and the theory of mixtures. A thermodynamic variational principle is constructed. All the investigations concern only flows with a single temperature field. Copyright © 1996 …
Ventilation-Perfusion Ratio in Perflubron During Partial Liquid Ventilation
2010
BACKGROUND: Functional magnetic resonance imaging (fMRI) of fluorine-19 allows for the mapping of oxygen partial pressure within perfluorocarbons in the alveolar space (Pao(2)). Theoretically, fMRI-detected Pao(2) can be combined with the Fick principle approach, i.e., a mass balance of oxygen uptake by ventilation and delivery by perfusion, to quantify the ventilation-perfusion ratio (Va/Q) of a lung region: The mixed venous blood and the inspiratory oxygen fraction, which are equal for all lung regions, are measured. In addition, the local expiratory oxygen fraction and the end capillary oxygen content, both of which may differ between the lung regions, are calculated using the fMRI-detec…
Critical points of higher order for the normal map of immersions in Rd
2012
We study the critical points of the normal map v : NM -> Rk+n, where M is an immersed k-dimensional submanifold of Rk+n, NM is the normal bundle of M and v(m, u) = m + u if u is an element of NmM. Usually, the image of these critical points is called the focal set. However, in that set there is a subset where the focusing is highest, as happens in the case of curves in R-3 with the curve of the centers of spheres with contact of third order with the curve. We give a definition of r-critical points of a smooth map between manifolds, and apply it to study the 2 and 3-critical points of the normal map in general and the 2-critical points for the case k = n = 2 in detail. In the later case we a…
Designing theme-based tabletop exercise for identifying and dealing with coordination problems in emergencies
2016
Tabletop exercises (TTXs) are used to train managers and other actors to deal with emergencies. These exercises that focus on the organisational coordination are planned and controlled by exercise managers through scenarios with predetermined events that participants discuss and act upon. Such exercises may lead to actors being ill prepared to deal with dynamic and emergent situations and problems. To address this knowledge gap, we apply an action design research approach to develop a TTX structured around non-sequential themes instead of predetermined events, thus allowing the participants to identify their own problems during the exercise. Our research contributes to existing knowledge by…
Versatile Pedagogical and Social Activities of a Graduate of Riga Polytechnic Institute Jānis Stiprais (1870–1946)
2021
The research discusses continuous effort of a pedagogue, economist and journalist Jānis Stiprais (1870–1946) in his pursuit to obtain education and his versatile pedagogical activities in Tomsk (Russia), Tukums, Valka and Riga, as well as the contribution he made in such areas as journalism, folklore and social work. J. Stiprais shared his knowledge of economics gained at Riga Polytechnic Institute (RPI) with the students at the University of Latvia (UL), Latvia People’s University and Vilis Olavs Commercial School; in the first half of the 20th century he was the principal of educational institutions in Tukums, Valka and Riga, he also was one of the signatories of the Memorandum of the Cen…
CONTINUA LA QUERELLE GIURISPRUDENZIALE SUGLI EX LETTORI DI LINGUA STRANIERA
2019
L’articolo analizza l’evoluzione della giurisprudenza multilivello sul rapporto di lavoro degli ex lettori di lingua straniera, oggi collaboratori linguistici: dopo una ricostruzione diacronica della legislazione di riferimento, l’A. sottolinea come la giurisprudenza – alla luce dei principi di libera circolazione e parità di trattamento – abbia arginato le discriminazioni di cui sono stati ripetutamente vittime gli ex lettori in ragione di un quadro normativo frammentario e disorganico. Infine, il saggio si sofferma sul più recente indirizzo di legittimità, che sulla base di un’interpretazione estensiva del dettato normativo ha equiparato il trattamento retributivo dei lettori stabilizzati…
Framing the public: the policy process around xenotransplantation in Latvia and Sweden 1970–2004
2011
A crucial debate is under way concerning the public's participation in biotechnology decision-making processes. This study, concerning the policy process around xenotransplantation (XTP) in Latvia and Sweden in the period 1970–2004, focuses on how scientific experts and politicians view the public and the public's participation in the process of developing policy regarding XTP. Drawing on interviews with actors involved in XTP in each country, we analyse and explain the inclusion and exclusion of publics in policy decision-making processes. In particular, we highlight the significance of the role of scientists and politicians in generating discourses which exclude the public from participat…
Towards a test of the weak equivalence principle of gravity using anti-hydrogen at CERN
2016
International audience; The aim of the GBAR (Gravitational Behavior of Antimatter at Rest) experiment is to measure the free fall acceleration of an antihydrogen atom, in the terrestrial gravitational field at CERN and therefore test the Weak Equivalence Principle with antimatter. The aim is to measure the local gravity with a 1% uncertainty which can be reduced to few parts of 10-3.
Principal components for multivariate spatiotemporal functional data
2014
Multivariate spatio-temporal data consist of a three way array with two dimensions’ domains both structured, temporally and spatially; think for example to a set of different pollutant levels recorded for a month/year at different sites. In this kind of dataset we can recognize time series along one dimension, spatial series along another and multivariate data along the third dimension. Statistical techniques aiming at handling huge amounts of information are very important in this context and classical dimension reduction techniques, such as Principal Components, are relevant, allowing to compress the information without much loss. Although time series, as well as spatial series, are recor…
Functional Data Analysis in NTCP Modeling: A New Method to Explore the Radiation Dose-Volume Effects
2014
Purpose/Objective(s) To describe a novel method to explore radiation dose-volume effects. Functional data analysis is used to investigate the information contained in differential dose-volume histograms. The method is applied to the normal tissue complication probability modeling of rectal bleeding (RB) for patients irradiated in the prostatic bed by 3-dimensional conformal radiation therapy. Methods and Materials Kernel density estimation was used to estimate the individual probability density functions from each of the 141 rectum differential dose-volume histograms. Functional principal component analysis was performed on the estimated probability density functions to explore the variatio…